Taylor Richards is still not training fully and seems no closer to featuring for QPR.
Richards, 22, has made just one league start since being signed on a season-long loan from Brighton last summer.
Under the terms of the deal, Rangers are obliged to sign him on a permanent basis at the end of the season.
Boss Neil Critchley said: “Taylor can’t get himself going at the moment, which is really unfortunate. It’s been stop-start for him.
“All he can do is concentrate on improving his physical condition as quickly as possible.”
Richards has not made an appearance since the 2-2 draw with Reading on 14 January - and his four minutes as a substitute in that match is his only league action this year.
Critchley insisted: “He loves playing football and wants to get back into training as quick as possible.
“But we’ve got to make sure that, when he does, he’s not in a position where he’s going to break down, because that’s happened to him too many times this season.”