Tottenham Hotspur may have suffered another injury setback after Younes Kaboul was forced off while playing for the club's U21 side against Manchester United.

The French defender has been working towards a return to the Spurs first team following an injury ridden campaign which has seen him side-lined since early August, but limped out of the U21 clash with United on Monday evening which an upper leg complaint.

Kaboul was making his second appearance for the U21's following a successful run out against West Ham United last week, but was replaced early in the second half by Jack Barthram, as Tottenham went on to lose 1-0 to United, courtesy of a Ryan Tunnicliffe goal.

Younes Kaboul
Kaboul's return in doubt after being taken off in U21 clash.

The former Portsmouth defender, who has not appeared for Tottenham since an opening day loss to Newcastle United, had initially been expected to return before the end of 2012 after undergoing knee surgery, but a series of setbacks has seen one of the club's most impressive defenders from last season absent for the majority of this campaign.

A return against Manchester City this Sunday had been touted following the defender's successful return against West Ham U21's, where Kaboul enjoyed a trouble-free hour in defence. However those plans may be re-assessed by the Tottenham back room after the 27-year-old's withdrawal on Monday.

Andre Villas-Boas' hopes of leading his side to a top four finish have already been dealt heavy blows in the past weeks through injuries to key men in Jermain Defoe, Aaron Lennon and Gareth Bale. The talismanic Welshman was carried off on a stretcher during Tottenham's 2-2 draw with Basel two weeks ago, although Villas-Boas remains hopeful that the 23-year-old will return in time to boost the club's Champions League hopes as the season enters the sharp end.

Spurs are also without veteran defender William Gallas, who was also withdrawn during their Europa League clash with the Swiss side, but still have Michael Dawson, Steven Caulker and Jan Vertonghen at their disposal.