The talismanic forward has endured a frustrating time of it at club level in recent times, with the Red Devils having suffered a woeful 2013/14.
Rooney himself netted 19 goals in 40 outings, but was unable to keep his team in contention for a top four finish.
The England star has never really shone for the Three Lions at a major tournament, but Keane feels that he could use the hurt of the season just gone to shoot down the likes of Italy, Costa Rica and Uruguay in Brazil:
“Wayne’s not going into the World Cup on the back of a top season at United in terms of winning trophies, and you could say that for a lot of the England players.” He is quoted by the Daily Star.
“Wayne had a decent enough season himself. It might help him, he might use the frustration he has had at United this year to the benefit of England.”
Rooney is expected to play a pivotal role for England at the World Cup, with a slot alongside Daniel Sturridge of Liverpool up front expected.