Leeds United's on-loan Arsenal striker Eddie Nketiah has been ruled out of this weekend's trip to Kenilworth Road by boss Marcelo Bielsa.
The 20-year-old is United's joint top scorer so far this term along with fellow attacker Patrick Bamford, the pair having netted five goals each.
However, despite his impressive return, Nketiah hasn't started a Championship match for the Whites, his 10 appearances all coming from the bench.
A abdominal injury has kept him out since last month though, the England U21 forward not featuring for his club since the 0-0 draw with Sheffield Wednesday on October 26.
There was slightly better news on captain and Scottish international Liam Cooper, plus Northern Ireland winger Stuart Dallas though who had been struggling with groin and hamstring problems respectively.
Speaking ahead of the trip to Luton, Bielsa said: "We don't know if Cooper is going to play yet. Dallas and Cooper are healthy but we will have to see.
"Nketiah is not ready yet, but next week he will start working with the group.
"Gjanni Alioski is (also) good."
Experienced midfielder Pablo Hernandez is expected to be available after returning from a calf injury recently, but Leeds will be without Jamie Shackleton (quad) and Adam Forshaw (hip).