With United's season threatening to unravel early in the campaign, Rooney handed in a transfer request citing the club's lack of ambition as the reason behind his desire to leave.
But United manager Sir Alex Ferguson talked him round and England centre-back Ferdinand also had a word with his team-mate before Rooney signed a lucrative new five-year contract on October 22.
Ferdinand told The Sun: "Rooney staying was a big part of what we achieved this season. There was a sense of relief from the players, the fans, everybody. Wayne is one of the best three players in the world, so to have him on our team-sheet is a bonus.
"I spoke to him that week when he was thinking of going. You do it with a Manchester United hat on and explain what you think is best for the club and how you want him to stay.
"If he had left it would have been a very big hole to fill. I'm not saying it was unfillable because the manager always comes up with something and you trust in his judgment. But, more than anything, Wayne staying sent a signal out to every one of our rivals in the Premier League that the glimmer of hope they had of us falling away had gone."
But while Rooney only found form in the latter part of the season to help United win the title, his striker partner Javier Hernandez has been consistently finding the net since making his United debut in the Community Shield on the first day of the season.
And Ferdinand believes the Mexican striker should have received individual accolades for his contribution this season.
"If you were voting today, I'm sure Chicharito [Hernandez] would be Footballer of the Year, he's scored so many important goals. Whenever he's been on the pitch, he's produced something.