But Vikings are a resilient lot and Alistair Carmichael insists his appetite for the fight is undiminished and he is relishing the year ahead, leading the Battle for Britain.
It is just a few days since that televisual encounter when the heavyweight from Orkney whom David Cameron had sent into the ring to duff up the Nationalists, found himself being duffed up by an opponent half his size; physically, that is.
The live head-to-head with Nicola Sturgeon did not quite require people to watch from behind the sofa when an expression of bewilderment slowly swept across the Scottish Secretary's face as the Deputy First Minister began to pound him with political punches.
"I didn't actually think it was that bruising," declares Mr Carmichael with no sense of understatement. But he then admits: "It wasn't the greatest performance I ever put in. That personally annoys me because I feel I let them off the hook a bit. There will probably be dozens of these debates; judge me at the end of it not just after the first one."
Who was it who said politics was a blood sport? But the consensus is that if the No camp is to maintain its momentum in the court of public opinion, then the Secretary of State will have to up his game to avoid becoming a human punch-bag.
Asked what he had learned from the Sturgeon experience, Mr Carmichael pauses, looks at the ceiling of his oak-lined Westminster office and says: "From the debate itself, pretty obvious stuff; that I personally need to be better prepared for these things.
"From the commentary around it, I now have a better understanding of the extent that the Nationalists will always play the man rather than the ball. Does that change my appetite for the contest? Not a bit."
In order to give more punch to the pro-Union cause, Mr Carmichael believes that the fear some sectors of Scottish life have about speaking out against independence will dissipate in the New Year, that the pro-Union parties will next spring come together to form some sort of united front about what should happen post the referendum and, most intriguingly, that the silent English will finally find their voice and mount a "stick with us" campaign.
Pro-UK politicians, including Margaret Curran, Mr Carmichael's Labour Shadow, have recently urged Scottish businesses to get engaged in the independence debate with suggestions some are fearful that to do so might harm their prospects, given there is a Nationalist Government in Edinburgh.
The Secretary of State is blunt: "We hear increasingly about people, business voices in particular, being disinclined to enter the debate because they think they will be punished as a result."
Punished? Was he saying Scottish businesses were being intimidated by the SNP Government?
"Intimidation is a strong word but there is certainly heavy influence. And you can imagine a situation as the campaign progresses when the heaviness of that influence does become inappropriate."
He makes reference to the boss of a FTSE 100 company, who told the Scottish Government he could not make investment decisions in Scotland because of the uncertainty about the tax regime and revealed how "the mood of the meeting immediately became very dark; they became very aggressive".
"This is not an isolated incident," declares Mr Carmichael. "I hear of it time and again. It's always told to me in terms of 'we don't want you to talk about this publicly but'. So people are not yet willing to stick their head above the parapet."
So there is a fear factor here?
"There is very much. This is what business people tell me; that they are scared of the consequences for their business of getting on the wrong side of the Scottish Government."
Without naming names, he notes: "I see it in the media sector. I have seen media outlets feel constrained in their coverage."
Yet the Cabinet Minister insists Scotland's captains of industry will not be able to hold their tongues about their private "grumblings" over independence for much longer.
"They will not be able to sustain that position and you are going to have a wider range of people have a say. Business will start to articulate a view, which will be largely unsympathetic to the concept of independence. They will be prepared to take possibly a short-term hit for the long-term strength of their business."
He mentions the supermarket giants and suggestions they would put up food prices in an independent Scotland because of higher distribution costs north of the border.
"I see this as the first brick out of the dam. Anybody who operates a business over that border is going to be affected and the closer we get to polling day they will want to have their say and they will not be so easily cowed."
He says he is also eager for the pro-UK parties in Scotland to come together to form a united front to voters to convince them the process of devolution does not end with a No vote and a new process will begin the day after polling day.
"I'm keen this goes ahead but I can't control it because it involves other parties and no parties. The only party in Scotland that's opposed to devolution is the SNP."
Another part of the bolstering strategy will be hearing voices from beyond Hadrian's Wall. Sure the Scots have the vote but that does not mean the English, Welsh and Northern Irish have to stay silent. There will be, Mr Carmichael makes clear, a "stick with us" campaign.
"Another thing you will see changing in the coming year is you will hear voices from other parts of the UK; in that respect they will enter the debate in the way the First Minister of Wales Carwyn Jones has done. They will say as part of the UK family we respect Scotland's decision to stay or to go but they will insist they don't want her to go. That's a perfectly legitimate voice to have in the debate."
He alsO attacks what some feel is the SNP Government peddling the politics of difference, saying: "The characterisation of the debate by the Nationalists is that this is Scottish social democracy versus English Conservatism. I completely challenge that for a number of reasons. First of all, it assumes people will always vote in the same way, which we know is not the case because within living memory it was the Conservatives who were the only party to get 50% of the vote in Scotland, so these things change over time. But also, because there is a variety of views across England, Wales and Northern Ireland as there is within Scotland.
"This goes back to Douglas Alexander's article that, yes, as a Briton he wants to tackle social exclusion and poverty but he thinks that's as important in Preston as it is in Paisley."
But the Nationalists are clearly seeking to frame the referendum debate on their terms - that is to say, they are the agents of change and the pro-UK forces are the agents of the status quo. Is there anything the Coalition can put on the table to counter that view?
Mr Carmichael's eyes half close and he snaps: "This is where the Nationalists don't understand the terms of the debate because they have never been part of it. One of the great ironies of Scottish politics is the SNP is the only party that has never delivered powers to the Scottish Parliament. It's an anti-devolution party. They sat out the constitutional convention and did not want to know about the Calman Commission."
But then the minister says something interesting, noting how the "hard work of sitting down and thrashing out what the next tranche of powers for the Scottish Parliament inevitably happens on the other side of a No vote". There is nothing specific but reference to the "next tranche of powers" shows an intended direction of travel should Scots vote No.
Of course, the Nationalists insist a No vote would stop devolution in its tracks as the Coalition turns its face away from Scotland. They refer to £4bn of cuts mooted by the Commons all-party parliamentary group on tax.
Mr Carmichael huffs with incredulity. "Look, that's their own Project Fear. That's them scaremongering.
"This government is not going to touch the Barnett Formula. It's a mark of the desperation of the Nationalists when they advance that argument; they justify it with reference to an all-party parliamentary group, which is a collection of who wants to turn up on any given day. The only way of getting rid of the Barnett Formula is to vote for separation."
Highlighting a recent report that suggested North Sea oil and gas revenue would only raise half the amount that goes to Scotland through the Formula, he stresses: "The Barnett Formula is part of the positive reasons for remaining part of the UK."
So Mr Carmichael is up for the fight but what about his boss? Where, one has to ask, is David Cameron, who pledged to fight with his head, heart and soul to keep Scotland in the United Kingdom?
I suggest the Union does not appear to have strong foundations if its chief advocate appears feart to get involved in the fight. "That is an assertion but it has no foundation in fact," declares the Secretary of State.
So is the Prime Minister of Scotland going to get more involved?
"We still have nine and a half months to go," notes the Liberal Democrat MP. He then pauses. It seems mention of his Conservative colleague often causes the Lib Dems something of a problem?
"No, it doesn't cause me a problem but you're asking me to predict what the Prime Minister's diary is going to be for the next nine and a half months. But what he has said quite properly is that this is a debate to be decided in Scotland, debated by the people in Scotland, and he passionately wants Scotland to remain part of the United Kingdom.
"If I flip it on its head and turn the assertion back; if he were to take any other approach, you would be telling me he was being disrespectful to the people of Scotland, that he was telling them what to do and it was none of his business."
So as we enter 2014 we can expect Mr Cameron to take a more upfront role? Mr Carmichael bristles. "I don't accept the assertion that he is a backseat driver. He is the Prime Minister of the whole of the United Kingdom. He spends time in Scotland both personally and politically. He is completely engaged in the debate, I know because I speak to him about it.
"He will take the role he wants to take. Because I don't accept the premise that he is in the background here, I'm not going to commit to saying that he is going to do more or he will do things differently. His approach at the moment is absolutely right and appropriate."
As Scotland prepares to enter its year of destiny, does Mr Carmichael regard his role as the most important in British politics? "I'm not going to say I have the most important in British politics because I don't think that's a quantifiable proposition for anyone. My job has an importance and relevance in Westminster, Whitehall and in Scotland, which it has not had since 1999 and the introduction of devolution. So to that extent I absolutely relish being in the middle of it."
And yet history could regard the Scottish Secretary as the man who lost the Union if Scots were to be unconvinced by his case and vote Yes on a cold, wet Thursday next autumn.
Mr Carmichael lets out a belly laugh. "Well, yeah, if it goes wrong. I think that it was Napoleon who said: 'Success has many fathers, failure has only one.'. I know that. I knew that when I took the job on."
It is never wise to make reference to the French emperor, who got his comeuppance in a Belgian field 200 years ago and spent his later years exiled on a rock in the South Atlantic.
The Secretary of State goes on: "No individual is going to win or lose this debate, no political party is going to win or lose this debate. This has got to be a debate all of Scotland has a voice in because if we, the Scottish people, leave it to politicians and the political parties, then it will become a pretty sterile and pointless exercise. Scots from all stripes and all backgrounds need to have their say."
So when the heat of battle has finally cooled and we know who has won and who has lost, where will the Secretary of State be on September 19 2014? Orkney, Edinburgh, St Helena?
"I would expect on September 19 to be on Orkney and I would expect to be having dinner with my wife because September 19 is our wedding anniversary. It will be 27 years to the day since we formed our own union in a little church in England outside Bath."
So the Carmichaels might be celebrating the success of two unions?
"I devoutly hope so."