Guy Whittingham is weighing up promoting Adam Webster to the centre of his defence.
Ricardo Rocha is struggling to make tomorrow’s trip to Brentford with a hamstring problem.
Sam Sodje would be the natural replacement should the veteran fail to declare himself fit.
However, Whittingham admitted Webster was also in his thoughts as a Griffin Park alternative.
The 18-year-old was part of a back three in the 5-0 defeat at Swindon on New Year’s Day but has primarily played at full-back.
Both Michael Appleton and Steve Cotterill believed Webster’s future role would be as a central defender, an opinion shared by Whittingham.
The caretaker boss watched the youngster in action at centre half for the Academy in their 2-0 win against Dagenham & Redbridge this week.
And he is considering him in the same role for the first team.
He said: ‘With Ric it is his hamstring. I wouldn’t say he is a big doubt. he is probably a 50/50.
‘That would mean either Sam (Sodje) or Adam Webster coming in.
‘Adam had a good game for the under-18s the other day, I thought he did well.
‘We have got to find out if he can play centre half, sooner or later you have got to find out these things.
‘He has been playing right-back to get him used to the first-team environment and the pressure that involves.
‘But eventually you have got to find out whether he is good enough to be a centre half in this league.
‘He is very good on the ball, quite composed and is 6ft 3in or 6ft 4in which is an ideal size. That can be his position.’
Webster has made 20 appearances so far this season, with 13 starts.