QPR expect to be without Sam McCallum until the middle of next month.
The on-loan Norwich youngster suffered a hamstring injury during the recent Carabao Cup win against Everton and missed Friday’s defeat at West Brom.
McCallum has also been ruled out of Tuesday’s home game against Birmingham and will not return before the international break.
The earliest he will be available again is the derby at Fulham on 16 October.
Lee Wallace, who has been out with a hamstring injury of his own, could also be back then.
And Sam Field is on course for return from a knee injury later next month.
“They (McCallum and Wallace) are probably two or three weeks away, so the international break gives us a window to try and get a couple of boys fit,” said manager Mark Warburton.
“Sam (McCallum) and Lee will probably be looking to come back around the same time, with Sam Field not far behind.
“With a hamstring injury you’re usually going to be out for three to four weeks.
“If it’s a very low-grade one you can get away with seven to 10 days. Anything above that and you’re looking at weeks longer.”
With McCallum having joined Wallace on the sidelines, Warburton deployed Yoann Barbet on the left flank at West Brom.
But he could choose a different option against Birmingham.
“It was only because we knew the physical threat - the set-pieces and the long throws coming in - and you’ve got to deal with it. They (West Brom) have got some real good power and physicality," Warburton explained.
“We dealt with that. In the end it was an individual error that cost us. So that side of it worked.
“Did we lose out on the footballing side? Yes. But they expected us to play football and we wanted to mix it up.
“For long periods of that game that worked and we were comfortable with the game plan. But we played less football for a reason. We have to show we can mix it up as well.”
Meanwhile, work at QPR's new training ground in Heston is scheduled to begin later this week.