Sir Alex Ferguson has revealed the one decision which caused him the biggest dilemma of his career.
The veteran Manchester United boss has been involved in management for almost 25 years, but insists the hardest call he has ever had to make came last May.
The Red Devils were preparing to face Chelsea in the UEFA Champions League final and Ferguson had to choose which members of his squad would face European heartache.
Of those that failed to make the cut on that memorable night, Park Ji-sung was perhaps the most unfortunate.
The South Korea international had featured heavily in crucial contests en route to the final, but failed to even make the bench in Moscow.
Ferguson insists that for all he has been through during an illustrious career, choosing between so many talented players that night gave him the biggest headache.
"It was a terrible decision to have to take," he said.
"In many ways it was the hardest decision I have ever had to make because Ji-sung had played such a great part in the previous games against Roma and Barcelona.
"But I had Owen Hargreaves for that game in Moscow and I felt he was the right one for that specific game.
"Then I had the decision of choosing our seven substitutes and which players could have an impact on the game.
"You look for a mix of defenders, midfielders and attackers and I opted to go with Nani ahead of Ji-sung, simply because I think Nani has got a goal in him. That was the only distinction and why I finally chose to go with Nani."