That is further proof, said two-time European Footballer of the Year Keegan, that no player can take their place for granted under Fergie.
"That has come out numerous times, not just with Wayne. No-one is indispensable," said Keegan. "United are not a one- man team and I don't think they ever have been a one-man team in their successful years.
"One guy might have to get player of the year - that's going to happen - but one-man teams don't win anything.
"You need five or six top-class players to win something and they have got something - and Rooney is one of them.
"The effect van Persie has had on Rooney is that United have won a championship. Rooney is not playing second fiddle to van Persie."