Central defender Drissa Diallo has suffered a setback in his recovery from the hamstring injury which has kept him out of action since before Christmas. The Guinean international limped out of training at the end of last week and will see a specialist.
Diallo told the club site: "I was training with the first team when I felt something in my hamstring and had to pull out.
"I've had a few days rest now and will see a specialist this week and take it from there.
"Hopefully it's not too bad, but I'll get some advice from the specialist and see what he says.
"It's very frustrating because I was training with the first team and hoping to play in the reserves this week but that's not possible now.
"I don't know how long I will be out for. It will be down to what the specialist says but I will be the happiest man around when I can get back to playing football and helping the team try to win promotion."
Diallo was due to play in this evening's reserve game against Coventry City at Nuneaton Borough's Manor Park (KO 7pm).
New loan signing Jimmy Juan will make his first appearance in a Town shirt against the Sky Blues.
The Monaco midfielder will be the only senior player involved with the rest of the first team squad away in Tenerife.