With first-choice goalkeeper Edwin van der Sar ruled out for several weeks with a broken finger, deputy Foster missed England's midweek friendly against Netherlands due to a knock.
However, Foster is set to return on Sunday, as is defender Brown following his thigh injury.
With Nemanja Vidic poised for another week out, Nani a doubt with a shoulder problem, Gary Neville struggling with a groin injury and Owen Hargreaves still some way off a return, the availability of Foster and Brown would be a significant boost for manager Alex Ferguson.
United are notoriously slow starters and have failed to win on the opening day in three of the past five seasons.
Ferguson knows that following a close-season in which Cristiano Ronaldo moved to Real Madrid for a world record fee of 80 million pounds and Carlos Tevez left for Manchester City, United will be firmly in the spotlight.
The Scot has limited his spending, with winger Antonio Valencia arriving from Wigan Athletic, striker Michael Owen joining on a free transfer from Newcastle United and midfielder Gabriel Obertan signing from Girondins Bordeaux.
SHOCK MOVE
Ferguson has been frustrated by the big transfer fees paid out recently and refused to match what Real Madrid were prepared to splash on France forward Karim Benzema before making his shock move for Owen.
Although many fans believe United will struggle to match the achievements of recent seasons, Ferguson says his squad are up for the challenge of trying to become the first club to win four consecutive Premier League titles.
Having lost the Champions League final to Barcelona in May, the Old Trafford team will not be distracted by the Club World Cup in mid-season and Ferguson feels that could be an advantage.
"We'd like to do it," said the Scot. "It would be a great achievement, obviously, because we all know what a difficult league it is.
"We accepted a good challenge last season, having to go to Japan for the Club World Cup in December and play catch-up.
"That was a great achievement to win it in the circumstances. But (this time) we don't have it and we don't have to play catch-up," added Ferguson.
United are sure to miss Ronaldo's goals but the players feel they will be an even more solid defensive unit as a result of the Portugal forward's departure.
Ferguson expects striker Dimitar Berbatov to improve and is confident Owen will prove his worth.
"Our approach to him (Owen) has been to say to enjoy being here, enjoy the training, and he has not missed a session yet," said United's manager.
"He has operated really well in all the games so far. He has shown some really clever stuff and I have been really pleased with him."
