Fergie's already under-strength back four was ripped to shreds when first Gary Neville and then Wes Brown limped off.
The injuries left United to see out the game with Ryan Giggs at left-back, Darren Fletcher at right-back and Michael Carrick partnering Patrice Evra in the centre.
But United still cruised past struggling West Ham thanks to goals from Paul Scholes, Darron Gibson, Antonio Valencia and Wayne Rooney.
And Ferguson said: "Evra must be the smallest centre-back in the world.
"But he's a good reader of the game. He's quick and determined.
"I don't know where I'm going to get a back four from to play Wolfsburg on Wednesday.
"Probably Nemanja Vidic will be back from flu and I'll play Carrick alongside him."
With Rio Ferdinand, Jonny Evans, Vidic and keeper Edwin van der Sar currently sidelined, Ferguson was bitterly disappointed to lose Neville and Brown.
He added: "The injuries in defence are becoming a bit of a headache to us.
"But Carrick stepped in and did very, very well. He's got the composure and the pace and it was a good performance in the second half.
"We used our experience to get the result."
Hammers boss Gianfranco Zola was clearly frustrated by the 4-0 defeat but was quick to pay tribute to United for an impressive display.
Zola said: "Their finishing was excellent, especially the first two goals.
"The first goal from Scholes changed the game and the second by Gibson was a fantastic strike.
"We tried to chase the game but I cannot be too hard on my players. They gave everything."
play berba in defence lol
Originally posted by Rock^Star:play berba in defence lol
LOL he'll stroll towards the on coming strikers.
I guess it isn't as bad lah... O'Shea, Evans are expected to be back by next weekend, Vidic probably by this Tue... Then there is still Rafael... Brown i think should be ok as well... But at least now we know Carrick can also play centre-back... lol
Yeah, the Rafael brothers are still there. Should be no problem for Fergie, he can always play 2-4-4 and go Gung-ho attacking.
If really need be, then rooney can play as a wing back or CB.
Wayne rooney can play almost anywhere... damn, even as GK.. DAMN!!!
well, Carrick seems to be a good choice, he got the height, pace, and passing..
he reminds me a bit like Rio..
Originally posted by Googooboyy:Yeah, the Rafael brothers are still there. Should be no problem for Fergie, he can always play 2-4-4 and go Gung-ho attacking.
It's da Silva brothers, not Rafael brothers.
Rafael da Silva and Fabio da Silva.
Defensive crisis deepens as Nemanja Vidic misses Wolfsburg trip
Nemanja Vidic has been ruled out of Manchester United's Champions League trip to Wolfsburg, leaving Sir Alex Ferguson with a threadbare defence as his team attempt to secure top spot in Group B.
GettyImages
Nemanja Vidic has been a stalwart for Sir Alex Ferguson
United had hoped Vidic would have recovered from the flu bug that kept him out of Saturday's win at West Ham. However, the Serbian was absent as the Red Devils checked in for the short flight to Germany, giving their manager a major headache.
His list of injured defenders includes skipper Gary Neville and England international West Brown, who both limped off at Upton Park, plus longer-term casualties Rio Ferdinand, John O'Shea and Jonny Evans. With the Da Silva brothers, Fabio and Rafael, also sidelined, the only orthodox defender Ferguson has in his squad is left-back Patrice Evra.
Ferguson has already revealed his intention to play Michael Carrick in central defence, while Darren Fletcher seems certain to occupy a defensive berth, too, although which one is open to debate.
Among the less familiar faces in the United party are Oliver Gill, son of chief executive David, Magnus Eikrem, Cameron Stewart, Matte James and Oliver Norwood.
Normally, Ferguson would only class outings such as this as useful staging posts in a young player's development. However, on this occasion, there is the very real possibility they could play a prominent part.
In addition to the defensive problems - first-choice keeper Edwin Van der Sar is also missing - Ferguson has taken the option of leaving Wayne Rooney and Dimitar Berbatov at home, meaning Michael Owen and Danny Welbeck are the only strikers in his 19-man squad.
Given Wolfsburg are unbeaten at home in this season's competition, it would appear United's best hope of finishing top would be for CSKA Moscow to beat Besiktas in Istanbul, which would leave the Red Devils at the head of affairs no matter what their result.
At least it should mean Paul Scholes should retain his place for a game the former England star feels will round off what has been a harder group than seemed likely when the draw was made.
"This was one of the toughest groups,'' he said. "We had to go to Moscow, which is always difficult, especially on a plastic pitch, and it is the same in Turkey, yet we managed to win both games.
"CSKA and Besiktas went on to prove at Old Trafford that they are very capable teams and, when you take into account Wolfsburg are the German champions, we did well to qualify as early as we did.''
He continued: "We want to win the game and finish top of the group. How much difference that makes to who we get in the next round, I am not too sure. There are lots of good teams at that stage of the tournament."
Let's go with this team against Wolfsburg:
Kuszcak
Fletcher Gibson Carrick Evra
Valencia Scholes Anderson Giggs
Rooney Berbatov
play valencia at RB as he is quick on the counter. fletcher at CB with carrick and evra.
gibson also can play cdm mah..
who knows if he decide to clear the ball from the halfway line and scores.
lol.