Manchester United midfielder Paul Scholes could miss the start of the season after the club confirmed he would undergo an exploratory knee operation which could keep him out for up to a month.

Scholes picked up a knock to his knee during his side's pre-season tour to Asia and headed home to Manchester five days early while his team-mates ran in six unanswered goals against Shenzhen.

Manager Sir Alex Ferguson told MUTV: "Paul fell on his knee in the last game. We've sent him home for arthroscopy to see what kind of damage there is.

"We don't think it's serious but it could keep him out for three weeks or a month."

Speaking about the match, which saw a debut goal from summer signing Nani as well as strikes from Ryan Giggs, Wayne Rooney and Cristiano Ronaldo, Ferguson said: "It was a good performance in spells and the humidity was quite high.

"Some of the goals were very good.

"We wanted to use as many players as we can and it was an exercise to get everyone fit. They have all had their share and it's been good for us that way.

"In our first game (of the tour) there was a bit of rustiness but in the last two games we haven't looked like conceding."

United defender Wes Brown hailed his side's efforts after the performance.

Paul Scholes' injury - and early return to Manchester - overshadowed the result, England international Brown believed the scoreline bodes well for the coming season.

"It was a good game and six goals is good in pre-season," he told MUTV.

"We have a good squad now. It was a good test but we played well to a good tempo and in the end they couldn't handle us."

Looking ahead to the coming season, Brown said: "For myself I want to play as many games as possible and when I do play to play well.

"I hope as a team we can win trophies again.

"We have a good squad now. Nani played well and fitted in fine on his first game.

"It's good for the whole season for the squad and shows what a player he is. We need players who can come on and change the game.

"The signings have done well, obviously Owen (Hargreaves) and Anderson are still to come in, but they have fitted in well."