QPR boss Marti Cifuentes said he was "very concerned" after star player Ilias Chair picked up a hamstring injury against Middlesbrough on Tuesday.
The 27-year-old winger missed the beginning of the season, and the whole of pre-season, with a back problem and then injured his knee after just five appearances in October.
The Moroccan has been unavailable for 12 Championship matches this season in all through injury and was replaced by Kader Dembele in the 55th minute of the 2-1 defeat at the Riverside.
"I'm very concerned, he felt his hamstring immediately and we have to do some tests, but usually these kind of situations it's going to take some time, but we'll do some scans and see what it is," Cifuentes told BBC Radio London.