The England striker netted after just 54 seconds at Old Trafford but hobbled off soon after scoring and will be sidelined for at least three weeks, manager Alex Ferguson said.
"Unfortunately we lost Wayne Rooney and Carlos Tevez came on and did fantasically for us then he got injured. It was a test of our character for the last half hour because it was an absolutely brilliant performance by Wigan," Ferguson told Sky Sports News.
"When the big boys start circling and coming and nicking your players, unfortunately if they pay enough they are always going to get their own way," Bruce said.
Rooney's first minute strike came after a good run and cross from newly-crowned FIFA World Player of the Year Cristiano Ronaldo although that was virtually Rooney's last contribution as he limped off eight minutes later.
He was replaced by Carlos Tevez who had a great chance to double United's lead soon after coming on but lost control of the ball after rounding Wigan keeper Chris Kirkland.
They tested goalkeeper Edwin van der Sar with a volley from Maynor Figueroa and almost drew level with nine minutes left when Antonio Valencia's drive just went over the bar.
UNITED FANS! Check FourFourTwo.com’s ever-expandinginterviews archivefor more stuff to read:
Web Exclusives Wayne Rooney, Peter Schmeichel, Carlos Tevez
Q+A Wayne Rooney, Cristiano Ronaldo, Ruud Van Nistlerooy
One on One David Beckham, George Best,
Ask A Silly Question Bryan Robson
Boy's A Bit Special Danny Simpson
Perfect XI Garth Crooks, Bryan Robson, Sir Bobby Charlton, Eric Cantona
What Happened Next? David May, Norman Whiteside
Sing When You’re Winning Dominic Monaghan, Ian Brown
And Another Thing Being a Big Four fan
