QPR striker Andy Johnson is likely to miss most of the rest of the season after suffering an anterior cruciate ligament injury.
The 31-year-old limped off in the 32nd minute of
Saturday's goalless draw against Chelsea
at Loftus Road.
Johnson was making only his fourth appearance for the club since his free transfer from Fulham in the summer.
Bobby Zamora, Jamie Mackie and Djibril Cisse remain as available attacking options for manager Mark Hughes.
Although he made 33 appearances for the Cottagers last season, Johnson
had exploratory knee surgery midway through a 2009-10 campaign dogged by injury.
The former Birmingham, Crystal Palace and Everton forward has represented England eight times, although he is yet to score.