Wayne Rooney is doubtful for Manchester United 's Premier League game against Sunderland on Saturday but Dutch striker Robin van Persie could return, interim manager Ryan Giggs said today.

Rooney is one of several players who have picked up a bug this week.

"Wayne has also got a tight groin so obviously with the bug you have to be careful because his immune system is down," Giggs told.

"Wayne, being Wayne, wants to play, so we'll monitor it over the next 24 hours."

There was better news of Van Persie , whose hamstring injury has kept him out for more than a month since scoring a hat-trick in the Champions League victory over Olympiakos.

"Robin's back in training and has looked really good this week," Giggs said. "Whether it's too early tomorrow we'll have to see."

The 40-year-old Giggs, who has played nearly 1,000 times for his only professional club, declined to say whether he would pick himself in a rare example of a player-manager appearing in the Premier League.