Former Manchester United boss Sir Alex Ferguson admits he blew the 2011 Champions League final against Barcelona.

Ferguson admitted he still regrets not specifically using Park-Ji Sung, who he named as one of the most underrated players he has worked with, to mark Lionel Messi from half-time at Wembley.

"That's where I lost the final against Barcelona at Wembley," said Sir Alex during a video Q&A for SPORTbible.

"I should have changed at half-time and put Park Ji-Sung 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 Park against Messi, I think we'd have beat them. I really do."