Former United midfielder Jonathan Greening is the latest addition to a 10-player injury list with the knee problem suffered during the weekend FA Cup tie with Burnley

Albion have four centre-backs definitely ruled out and it means Ryan Donk is likely to be pressed into action at The Hawthorns despite limping out of the cup game with a groin problem.

But Mowbray has vowed to remain competitive against the Red Devils who beat them 4-0 at Old Trafford earlier in the campaign after a goalless first half.

The former Hibernian manager said: "Our home record in recent months has been pretty good. You have to go back to the Chelsea game in mid-November to find the last time we lost at our place.

"We have won a few games and drawn a few. We go into the game hoping to give Manchester United an uncomfortable night.

"United haven't been as free-flowing and there have been a few games recently where it has been 1-0 or 2-1.

"If we can make it a tight game for them and a nervous game for them, the longer it goes, you never know in football.

"We are at home, we will have our supporters passionately behind us. Sometimes the fans can make that difference and make it edgy for the away team.

"Of course, we won't be able to put our strongest side out which is a blow to us. When you play Manchester United, you'd like to play your very best team and give it your best shot but I am sure the team we put out will be very competitive.

"We will have a look and I will come up with a shape and a system to go and play Manchester United and try to give them some problems, although it is easier said than done."

Mowbray played down talk of United's own fitness crisis.

He added: "I know United have one or two injuries to key players like Wayne Rooney and Rio Ferdinand at the moment.

"But when I looked at the squad they put out at the weekend, it didn't look too weak when you've got Berbatov, Tevez, Ronaldo, Giggs, Scholes, Carrick, Vidic, Neville et cetera.

"It doesn't seem to be hurting them too much at the moment."

Mowbray knows having so many players sidelined will earn him little sympathy if United turn on the style at The Hawthorns and chalk up a resounding victory.

He said: "Having injuries is part of the job. Hibs had a Scottish FA Cup semi-final against Hearts at Hampden Park with seven first-team players not available. It was not easy and we lost 4-1.

"The score is the only pertinent thing and, if we lose on Tuesday, no-one is really interested that certain players are not playing.

"It is just the scoreline that goes into the history books and if you lose, then you've got to move on to the next game."

Whatever side he puts out, Mowbray is adamant Albion will continue to try to play fluent football rather than sit back and contain Sir Alex Ferguson's side.

He said: "We did fine at Old Trafford for an hour and lost 4-0.

"When you lose the ball to United, they don't give it back very quickly so invariably you are forced on the back foot even though you want to be positive. They just pen you in.

"Will we change our style of play? No, I don't think so. If you haven't got the players to play that way, you don't play it.

"If we haven't got overly competitive players to get physical with them or condense things, you can't play a game that you haven't got the players for."