Manchester United lost Marcus Rashford to injury as they beat Wolves 1-0 in an FA Cup third-round replay at Old Trafford.
Star striker Rashford started from the bench just four days before a crunch Premier League clash with leaders Liverpool, but he was introduced as a substitute three minutes before Juan Mata scored the only goal on Wednesday.
The England international appeared to be nursing his back and, after initially attempting to play on, had to be replaced with 10 minutes remaining.
The issue provided a disappointing end for Ole Gunnar Solskjaer, whose side came through a replay after drawing the first clash 0-0 earlier this month against the opponent that knocked them out of the cup last year.