The Atletico Madrid man is currently starring for Uruguay who have made it through to the final four of the World Cup and Ferguson said that he wished him well the other day ahead of Tuesday night's semi-final against Holland.
Ferguson acknowledged the fact that Forlan did not have much of an influence at Old Trafford during his stay in between 2002 and 2004 but said the 31-year old had excuses.
"I sent him a text the other day. He's been fantastic and we're all proud of him," Ferguson told SunTalk.
"There was never a problem with him at Old Trafford, it was just the combination of him and (Ruud) Van Nistelrooy did not work.
"The boy had other issues, his sister's health in Spain. He always wanted to get to Spain at some point. The only criticism of ourselves was that we sold him too cheaply.
"He could have been a hero. He was a great lad, a magnificent professional, spoke five languages and was a great tennis player."