Sir Alex Ferguson believes Manchester United would have won the Champions League in 2011 if he'd instructed Park Ji-Sung to man-mark Lionel Messi.
United lost the game at Wembley 3-1 to a Messi-inspired Barca, who beat them for the second time in three years, having won 2-0 over Ferguson's side in Rome, 2009.
But Ferguson believes Park, who often performed specific tactical roles in big games for United, could have shackled Messi that night. Wayne Rooney levelled for United to make it 1-1 at half time, before Messi and David Villa secured the win for Pep Guardiola's superb Barcelona team.
"That's where I lost the final against Barcelona at Wembley," Ferguson explained in an interview with Sport Bible. "I should have changed at half-time and put Ji-sung Park on Messi.
"That was a mistake... I was going to do it at half-time, then I said, 'Well, we just equalised before half-time, they may see the game differently, we may grow into the game better.'
"We were actually quite good in the last 10 minutes of that half. We came into it and we could have been in front.
"But if I'd played Ji-sung Park against Messi, I think we'd have beaten them. I really do."
Ferguson ended his career with two Champions League trophies, having won it in 1999 and 2008, but also lost two finals. He won 13 Premier League titles with United and his life and career has been documented in a new film, 'Never Give In'.
