Tomlin returned from a month-long absence with an ankle injury against Colchester last weekend but the forward was sent off for violent conduct early in the second half of the 1-0 defeat in Essex and must now serve a three-match suspension.
Midfielder Danny Kearns has been ruled out with a hip problem but right-back Mark Little is fit after his recent hip issue.
Leaders Leyton Orient are set to be without Mathieu Baudry when they head to third-placed Peterborough. The French defender is carrying a knee injury which forced him to miss last weekend's 1-0 win over Rotherham.
Gary Sawyer came in at left-back against the Millers with Scott Cuthbert moving across to replace Baudry at centre-half.
Top scorer Kevin Lisbie overcame a bruised leg to score Orient's winner and will lead the attack again in what is likely to be an unchanged starting line-up.