Tomlin (groin) was replaced before half-time in the 3-0 home win over Oldham which assured the club's League One status for another term last Saturday.
On-loan Bristol City midfielder Gavin Williams, who scored twice last week and has now hit five goals in seven games, is also an injury concern.
Williams has still not fully recovered from an ankle injury that he carried into last Saturday's crucial win.
If both players are ruled out then Dean Bowditch is set to start as the lone striker as target man Sam Williams (knee) is still sidelined.
The Glovers are again set to be without on-loan Swansea midfielder Shaun MacDonald (groin).