Manchester United boss Sir Alex Ferguson has conceded his gamble on Owen Hargreaves turned out to be a "disaster".
Hargreaves made his first start for United in two years after being a shock inclusion in the side to face Wolves at Old Trafford on Saturday.
However, Hargreaves' return lasted less than five minutes as he was forced off with a hamstring injury.
The injury was the latest blow to hit the England international who has been battling with serious knee problems during the last two years.
Ferguson admits the gamble on Hargreaves' fitness backfired badly as his side managed to overcome Wolves with a last-gasp winner from Ji-sung Park.
"We took a gamble with Owen Hargreaves," said Ferguson.
"We thought by doing that it would give us a compact midfield with experience. But he only lasted five minutes. It was a disaster.
"He has hurt his hamstring, which is unbelievable."
Meanwhile, United team-mate John O'Shea has backed Hargreaves to bounce back from the latest setback after admitting his sympathy for the midfielder.
"We feel so sorry for him," O'Shea told MUTV.
"He was so looking forward to it and we were really excited for him as well after all the hard work he's put in.
"We just have to wait and see exactly what the injury is, but he'll be back again, no doubt about that.
"He's worked very hard to get to this point and I'm sure there'll be a few little niggles - he's just got to get over them quickly."