Defenders Michael Nelson and Adam Drury and midfielder Stephen Hughes all came off against MK Dons on Monday night to leave Lambert with selection issues.
Nelson has an ankle injury and is unlikely to feature while Hughes has an Achilles problem and is rated as doubtful.
However, left-back Drury has had treatment on a hip injury and should be fit to keep his place in the starting XI.
Midfielder Darel Russell is back in training after a calf problem but will not be considered but fellow midfielders Matt Gill (knee) and Owain Tudur Jones (calf) continue to miss out.
Full-back Rhoys Wiggins (knee) is back in training but is not yet fit enough to be considered for his debut.