Ferguson led his United side to five Premier League titles and one Champions League during his tenure, in what is widely deemed as one of the best stints in football history. However, despite the tactics on the pitch, Rooney has revealed that one game helped more than anything off of it.
The game helped tactically
Speaking on his BBC podcast The Wayne Rooney Show, the former England international stated that playing five-versus-five on the army game SOCOM on the PlayStation Portable helped United immensely.
"I really believe a big part of our success was playing on the PSP," said Rooney, who won five Premier League titles and a Champions League under Sir Alex Ferguson.
"It got us communicating more - we used to play it on the plane, on the team bus.
"It would be me, Rio (Ferdinand), Michael Carrick, John O'Shea, Wes Brown. You have to talk, you have to tactically be right, go and revive people when they get killed and it was a massive part of our success - ask any of those players, it was brilliant."
Van der Sar was not a fan
Despite their success, Rooney did admit that one United player was not a fan of the game and was often frustrated by his teammate’s behaviour on the team bus.
"How you played that game reflected that player, how they play the game. Michael Carrick was a little sneaky calm one, you would be lying down hiding and you'd hear a little grenade bouncing by where he'd thrown it. I was just all in, straight in, frontline of the trenches, get in there.
"Edwin van der Sar used to get annoyed, because we're on the team bus and there's just shouting on the team bus all over the place where you are telling people where you are. Sometimes if they have got one player left, you communicate, so you flank them, go and get them. Van der Sar used to get annoyed and move, he used to try and get as far away from us as possible!"