IF ever a season has highlighted the unique demands which there are on the players, manager and hierarchy of Celtic then this has been it.

The Glasgow club sewed up their fifth consecutive Scottish title with three games to spare with victory over Aberdeen at Parkhead yesterday. The celebrations both in the stands and on the pitch were joyous.

But deep down are their fans content? Not at all. Just about everybody at Parkhead, from the team to the coach to the chief executive to the major shareholder, has got it right in the neck off the supporters in recent weeks.

Their unhappiness with Ronny Deila, Peter Lawwell, Dermot Desmond and others could be considered harsh given just how comfortable a margin Celtic have won the Ladbrokes Premiership by.

What other club’s fans would, as happened against Ross County last month, respond to a convincing league win with giant banners slating the key protagonists and a silent protest? There are precious few, if any, in the world.

But, in truth, many of the complaints have been more than justified. Deila’s side could and should have performed far better in the league than they have done in the 2015/16 campaign given that their budget has once again dwarfed those of their opponents.

With Rangers missing from the Premiership, Celtic have no serious challengers to their domestic dominance. They haven’t just been required to win it in the absence of their city rivals to satisfy their followers in the last four seasons, they have been required to win it well. That hasn’t been the case this term.

With the team also failing to qualify for the Champions League group stages for the second season running, performing woefully in the Europa League, being beaten in the League Cup semi-final to Ross County and losing in the Scottish Cup semi-final to Rangers, it has been understandable that disenchantment has grown.

Deila, who announced last month that he would be standing down as manager at the end of the season, has been highly fortunate to survive for as long as he has. Several of his squad members, those who have underperformed and those who haven’t featured, will be moved on along with him in the summer when his successor is appointed.

Aberdeen once again launched a spirited challenge in the Premiership and have finished up as the best of the rest for the second season running. Their squad, though, hasn’t been deep enough or good enough to sustain their bid to win a first Scottish title since 1985 for 10 months.

On their day, Aberdeen have been as assured as any team in the country, every bit as impressive as this Celtic side. They have certainly, with Simon Church, Niall McGinn and Adam Rooney in their ranks, had goals in them. But their inability to cope with the loss of key personnel has shown.

A limited defence, too, hasn’t helped their cause at times. What would their manager Derek McInnes have given to have centre backs as reliable as Alex McLeish and Willie Miller? John Inglis and Zander Diamond would have been a distinct improvement on what has been at his disposal.

Losses to Inverness Caledonian Thistle, Motherwell, Hearts and St. Johnstone in the second half of the season have cost them dearly and effectively allowed Celtic to prevail.

McInnes’s side certainly kicked off their Premiership campaign impressively back in August – their eight game winning run was the best start to a league season Aberdeen had made in their entire 112-year history.

Triumphs over Dundee United, Kilmarnock, Motherwell, Dundee, Partick Thistle, Celtic, Hamilton and Hearts had overjoyed Dons fans daring to dream that maybe, just maybe, they could pull off the impossible.

They performed far better than the defending champions in a rousing encounter at Pittodrie in September despite falling behind to a Leigh Griffiths penalty just before half-time. A well-taken Rooney spot kick and a Paul Quinn strike from a few yards out with just four minutes remaining secured a 2-1 victory in front of a crowd of 20,385.

But a mini-slump in form soon ensued. Celtic claimed top spot in the Premiership with a 1-0 win over Motherwell in October the day after Aberdeen had been defeated by Ross County in Dingwall and didn’t, despite their best efforts, relinquish it thereafter.

The Aberdeen and Celtic games on March 19 were crucial to the outcome of the Premiership. Deila’s side performed poorly against Kilmarnock at Rugby Park, but sneaked a 1-0 win thanks to a long-range Tom Rogic strike in the last minute.

If they had ended up drawing that game, as they perhaps should have done, then McInnes’s men would have had the opportunity to leapfrog them into top spot. But they lost 2-1 to Motherwell at Fir Park later that day. It was a double blow from which they wouldn’t recover.

There have been success stories at Celtic this season. Leigh Griffiths has flourished despite operating as a lone striker in a 4-2-3-1 formation and has been Scotland’s top scorer by a distance. He will collect multiple Player of the Year awards.

Kieran Tierney, the teenage left back from the Isle of Man, has performed above his tender years and established himself as a first team regular. He will pick up all the Young Player of the Year gongs. Rogic has also, after struggling to establish himself for several seasons, come to the fore.

But many more have failed to impress. The quality of football served up by a team has often been poor. How would Celtic have fared without the goals of Griffiths? It doesn’t bear thinking about for their fans. None of their other players has even managed to get into double figures.

Aberdeen defeated Celtic 2-1 for a second time at home in February. For a side that had lost all four of their league games to the defending champions the season before it was a definite improvement. But it just wasn’t good enough.

Despite making it five-in-a-row, many at Celtic have thought exactly the same thing about their side. There will need to be a significant upturn when a resurgent Rangers return to the top flight next season.