The defender went for scans yesterday amid concerns he has broken the fifth metatarsal and expects to find out on Monday whether he will be out for as long as three months.
That would leave Brown with little or no game time prior to the World Cup and may even open the door for team-mate Gary Neville to make a remarkable return to the England squad.
Crocked: Wes Brown fears his World Cup dream is over after breaking a bone in his foot during United's 1-0 win over Wolves on Saturday
Neville, 35, replaced Brown at half-time on Saturday after the 30-year-old had been injured in a challenge with Wolves' Matt Jarvis. Brown, who left Molineux with the foot immobilised in a protective boot, has been dogged by injuries.
He broke a metatarsal just over 12 months ago and missed a chunk of this season with a hamstring problem.
Yet he looked to have timed his recovery to perfection after he was called up to the England starting line-up at right back by Fabio Capello to face Egypt last week with Glen Johnson still out injured with medial knee ligament damage.
England recall? United veteran Gary Neville
Johnson is expected to return to Liverpool's first team in around two weeks' time and will cement his position as Capello's first choice right back barring any setbacks. But Capello is already without Ashley Cole and Wayne Bridge and was banking on Brown's versatility to give expert cover to his depleted squad.
His steady performance at Wembley last Wednesday looked to have guaranteed selection for South Africa but his injury jinx looks to have struck again.
The situation will be an obvious concern to United manager Sir Alex Ferguson too in the week that they face AC Milan in the Champions League and title defining games in the Premier League against Fulham, Liverpool and Chelsea over the next month.
Rio Ferdinand and Nemanja Vidic are nursing their way back to full match fitness but have been troubled by niggly injuries all season.
Questions have been posed over Jonny Evans's form and although John O'Shea is hopeful of making a return from a blood clot, that is not expected until late April at the earliest.
Back in business: Rooney should be fit to face AC Milan on Wednesday
Wayne Rooney did train yesterday despite his knee injury and is hopeful of being passed fit to face Milan on Wednesday after sitting out the 1-0 victory at Wolves.
Meanwhile, Ferguson dismissed a report that he was supporting the proposed Red Knights takeover of the club from the Glazer family. Ferguson said: 'It's absolute rubbish. Not an ounce of truth in it.'
However, he would not dismiss their bid, adding: 'I am quite friendly with a couple of them. If they want to try and buy the club it's entirely up to them.'
David Beckham: AC Milan can still beat Manchester United in the Champions LeagueWolves 0 Manchester United 1: Scholes in the 100 club as Berbatov shows a ton of classManchester United in swoop for Belgian defender Vermijl from Standard LiegePiers Morgan: John Terry wins the Oscar for best original score, the Inglourious B*****d!MANCHESTER UNITED FC