Nemanja Vidic travelled with the Manchester United squad for their Champions League visit to Romania on Monday while fellow central defender Rio Ferdinand remained at home, the club confirmed on their website.
Vidic has not played since suffering a calf injury in their opening game of the season against West Bromwich Albion on Aug. 14.
He should return for the Group C match against Otelul Gelati which United need to win to kick-start their campaign after two draws against Benfica and Basel.
Vidic played for Serbia in their Euro 2012 qualifying defeat to Slovenia last week, but manager Alex Ferguson resisted the temptation to bring him back for Saturday's Premier League game against Liverpool at Anfield.
Ferdinand, who will be 33 next month, played the full 90 minutes against Liverpool and there were no reports of any injury problems following the match that ended in a 1-1 draw.
The England international also missed United's previous away match in the Champions League against Benfica a month ago, but was in the side that drew 3-3 with Basel on September 27.