Midfielder Brian O'Neil (knee) and winger Joe Anyinsah (thigh) are not yet ready to return but will step up their performances in the reserves.
QPR are confident midfielder Martin Rowlands will recover from a groin injury for the trip to Deepdale.
Defender Dominic Shimmin could be in the squad after completing a three-match suspension.
BBC
QPR are confident midfielder Martin Rowlands will be back for the trip to Preston.
Rowlands was taken off during last weekend's 2-0 win over Southend complaining of a groin injury, but Rangers will give him until the last minute to recover.
Manager Gary Waddock also hopes to receive international clearance in time to have summer signing Egutu Oliseh available for the match at Deepdale.
Defender Dominic Shimmin could be in the squad after completing a three-match ban, but forward Marc Nygaard (back) and goalkeeper Simon Royce (groin) are still out.
Rangers were impressive in beating Southend, but Waddock warned: "We are only three games into a season. We have achieved nothing yet - and won't until at least the end of the campaign.
"Preston have been there or thereabouts for the last two season, so it is a tough game, but it is one we are looking forward to."
Sporting Life