Manchester United manager David Moyes has revealed star striker Robin van Persie is a doubt for Saturday's Premier League clash against Southampton.
Van Persie suffered a calf injury while in action for Holland against Turkey in midweek after previously suffering a toe problem before the international break and he is not certain to recover in time for the champions' meeting with in-form Saints at Old Trafford.
"We have a few with knocks," Moyes told MUTV. "The one we are more worried about is Robin van Persie.
"He got a kick on the calf and he came off in the second game (against Turkey). He has had problems with his toes as well. We will see how he is."
Meanwhile, United's England players will return to club duty with a spring in their step after the national team secured qualification for next year's World Cup, but Old Trafford has not been a happy place in recent weeks.
With only two wins in their last six games, Moyes's side trail early leaders Arsenal by six points and in Southampton they face a team who have climbed to fourth place following a run of three straight victories.
A brace from teenage winger Adnan Januzaj gave United a 2-1 win at Sunderland in their last outing but Southampton are likely to present formidable opposition, having gone four games without conceding a goal.
Saints captain Adam Lallana has given Argentine manager Mauricio Pochettino the credit for their fine start to the campaign.
"We've had a full pre-season under him to get his tactics and methods across," Lallana told local newspaper the Daily Echo. "You're starting to see all the rewards of our hard work under the manager."
The top five clubs are in action on Saturday, with Arsenal hosting Norwich City, second-placed Liverpool visiting Newcastle United, third-placed Chelsea facing Cardiff City and Manchester City, who go into the weekend in fifth, travelling to West Ham United.
Liverpool manager Brendan Rodgers, whose side won 6-0 in the corresponding fixture against Newcastle last season, has revealed that he will have Glen Johnson, Joe Allen and Aly Cissokho available for selection again after injury for the trip to St James' Park.
Arsenal manager Arsene Wenger, meanwhile, says that club-record signing Mesut Ozil will undergo a fitness test on Friday after hurting his knee on international duty with Germany.
"He is alright. He came back with a knock on the knee but it was just a kick," the Frenchman said.
"We'll have a test (Friday) to see if he is fit enough for Saturday or not."
Gus Poyet will take charge of his first match as a Premier League manager when bottom club Sunderland visit Swansea City.
The former Chelsea and Tottenham Hotspur midfielder was appointed successor to the sacked Paolo Di Canio prior to the international break.
Poyet praised Swansea in regional newspaper the Sunderland Echo but said they had only one focus.
"At the moment though, it doesn't matter too much who we play, or where. Our position means that we need to go out looking for a win," he said.
West Ham manager Sam Allardyce has attempted to calm the excitement around young midfielder Ravel Morrison, who scored a fine solo goal in a 3-0 win at Tottenham before netting twice for England Under-21s.
"I have to be careful with the amount of publicity that Rav gets," Allardyce said ahead of the visit of City.
"They can have their ups and downs, they burst onto the scene, they can get lavished with praise and then lose their focus and, when they lose their focus, they can dip away again, and I don't really want that."
Tottenham visit Aston Villa on Sunday while Monday's fixture is a London derby between Crystal Palace and Fulham.