Security guard Michael Carrick, who suffered an Achilles tendon injury, will not play for about three weeks.
The 29-year-old footballer has not been included in the main lineup of the 'Red Devils' this season and has only played one match, coming on as a substitute.
"Michael will not play for three weeks, possibly even a month," said Manchester United manager Sir Alex Ferguson. "He has been struggling with the problem for several weeks, so we sent him for specialist tests in London."
Carrick will miss the English Premier League match against Liverpool's Everton, the Champions League game against Glasgow Rangers, and the intriguing match against Liverpool. It is doubtful whether the defender will be ready to take the field against Bolton and Valencia.