The former Arsenal front-man joined United in the close-season for a fee of 24 million pounds, and while he has been the one tricking opposing defenders this season, Rooney says he is the easiest target in the dressing room to play a joke on.

"I'd have to say Robin. He's not the brightest!" Rooney said to DHL.

"As much of a good footballer he is, he's definitely not the brightest off the pitch and it's just easy to get to him.

"There's a few who like to joke around. There's no-one who stays really quiet and out of it."

Meanwhile, midefielder Tom Cleverly has identified Rooney as one of the main pranksters at Old Trafford, along with Rio Ferdinand, Danny Welbeck and Anderson.

"Team jokers?" said Cleverley. "There’s a few characters in our dressing-room.

"Wazza (Rooney) is always taking your phone if you leave it lying about. Rio, Ando, Welbz (Welbeck), they're all bubbly characters. I just try to lay low and stay out of it."