Even Dave Brailsford and the rest of the Team GB cycling selectors may be reluctant to make the call. When the GB selection panel meet in Manchester on Thursday to choose the Olympic teams in all disciplines, arguably their toughest choice will be whether Sir Chris Hoy or England's Jason Kenny should be given the sole place in the men's individual sprint.
New regulations permit just one entry per nation per event at London 2012, and the selectors may find the decision so agonising that they leave both men to sweat until noon on August 3, the day before the competition begins. Both men would prefer to find out earlier than that, of course, in order to tailor their training programmes but MacLean, who won Olympic silver alongside Hoy in the team sprint in 2000, feels that his friend and countryman would have his work cut out to replicate the hat-trick of golds (individual sprint, team sprint and keirin) he won in Beijing.
More than that, MacLean feels the Olympic organisers have got it badly wrong in limiting the entries to one per nation, and are running the risk of the world's top athletes changing allegiance to another nation in order to compete at the top level.
"It is criminal, to be honest," the 40-year-old from Grantown-on-Spey said. "It would make a far better Olympics if it wasn't just one rider per nation, because it isn't just Britain it affects. Germany have got some fantastic sprinters, the same with France and Australia. Whatever happens, you will have lots of people sitting on the touchlines thinking 'that could have been my gold medal if I been given the nod'. It is unfortunate; situations like that could potentially cause people to look at the regulations and start switching nationality.
"Some people are essentially going to get a walkover in the first round because the gap between first place and last place in the qualifiers is going to be massive. It is a shame and it takes a bit of a shine off it, even for the guys who are lucky enough to qualify. Of course it is still a medal but to win gold on the day you want to compete against all the best riders in the world."
MacLean has watched Kenny develop since he was picked up by the sport's talent ID programme as a teenager and knows the two are worthy adversaries. The Englishman is 12 years younger and has placed higher than Hoy in the past two World Championships, taking gold and then silver.
"It is a really tough one to call for the selectors," said MacLean, pictured. "Chris would love to replicate what he did in Beijing, but it is going to be a big ask. I don't want to do him a disservice but I think Chris would be the first to admit that he would probably be happy just with one gold. Three is probably a bit of a stretch – even if it is do-able. If he gets the nod to participate in the sprint then it is because they think he can win it. I don't know how they are going to select it but they are going to have to make a call soon. I believe you can put a reserve in so it could go to the day before the event, depending on how their form has developed.
"Going in to the Olympics last time, they were aware from training they were going to be hard to beat in the team sprint if they did their best ride, but I don't think that is the case this time; they are on the back foot and playing catch up. So that will be tough, and the keirin is always a bit of a lottery."
Another Scot, Ross Edgar is likely to play his part in the team sprint, while MacLean himself hopes to be back on a podium this summer as a tandem guide to double Paralympic gold medallist Anthony Kappes.
"It is great that cyclists are in the limelight now but in terms of the Olympics coming to this country, my timing was slightly out – by about eight years," he said. "This is different and the biggest hurdle was the motivation, because it becomes more like a job, but I feel I have got my head round that now.
"You have to have a very close partnership with the guy you are riding with. You are both pedalling the bike, so you have to know each other fairly well and spend a lot of time together. Two medals are possible, but I think Anthony and I are both similar in that we are not gung ho. He is a double gold medallist from Beijing so he has nothing to prove but we both just want to see how fast we can make a tandem go."
Elsewhere in the GB squad, there is serious strength and depth. The selection committee are likely to name an eight-man team for the road race, with five making the final cut, and there will be much interest in whether David Millar, free to participate after the overturning of his drugs ban, comes in to play his part in chaperoning Mark Cavendish into the final kilometre. Bradley Wiggins, in outstanding form last week in the Dauphine, will also be included in the road race squad, although by the time London 2012 begins he will have endured the Tour de France, so his best chance of gold resides in the time trial.
Victoria Pendleton goes for three golds in the women's sprint events, while Geraint Thomas, the fast improving Welsh rider, will sit out the Tour de France to focus on the Team Pursuit.
Seven golds in Beijing have set the bar high, but MacLean can see more medals coming Britain's way.
"It is a formidable operation," he said. "They have got a few tricks up their sleeve, equipment-wise, and home advantage is with them. They are probably better prepared than they ever have been and won't have all the travelling they had for Beijing, so there are a lot of things working in their favour."