Blackburn Rovers boss Sam Allardyce fears a rejuvenated Wayne Rooney today against Manchester United.
Allardyce is worried the striker could put an end to Rovers' revival which has seen them win three of their last four matches.
He said: "I watched Wayne at Rangers and he looked very fit. It's almost like he's starting a new season now.
"You can see the energy he has and the more games he gets, the better he will get.
"We just hope he's not on top form as he's one of the world's most dangerous frontmen."
