Two-goal hero Wayne Rooney celebrated a personal milestone at Old Trafford on Saturday – but warned Manchester United they must buck up their ideas if their Premier League title challenge is not to end in disaster.

Rooney's salvo, in addition to goals from Robin van Persie and Danny Welbeck, allowed United to record a 4-2 win over Stoke.

It also took Rooney to 200 club goals – for United and Everton – an early present for his 27th birthday on Wednesday.

However, United found themselves behind for the seventh time in 11 games this season, and have now conceded seven goals in four Premier League home games.

And Rooney knows it cannot continue. He said: "Of course it is a concern. We can't keep doing that.

"No disrespect to Stoke, but better opposi-tion will punish us. We need to keep working and keep defending well.

"Hopefully soon we will get the players back who can provide a bit of cover for us because if we want to be successful this season, we can't keep doing that."

In diverting home Charlie Adam's free-kick for the first own goal of his career, Rooney was becoming the first United player to score at both ends since David Beck-ham at Blackburn in 2001.

Michael Kightly then struck after United had responded with three goals of their own, mean-ing Rooney's second was required to keep the Red Devils four points adrift of pacesetters Chelsea.

Rooney's partnership with Van Persie looks as though it will pay big dividends over the season.

"We are getting more of an understanding," said Rooney. "That is the first game we have started together up front and we have both scored. I am sure it will get better."