The 20-year-old picked up the yellow card, his fifth of the season, with just two minutes to go in their Johnstone's Paint Trophy victory over Wycombe, a decision manager Gary Johnson believes was a correct one.
"I thought it was a yellow card," he said. "He did dive, and if you dive then you've got to get a yellow card. That's how it was, but the less I say about that, the better."
While Marsh-Brown will serve his one-game suspension Johnson's options are boosted by the return of on-loan duo Paddy Madden and Dale Bennett.
The pair were cup-tied for the midweek clash having already featured in the competition but they will go straight back into the matchday squad with top scorer Madden likely to start at Huish Park.
Captain Jamie McAllister stepped back into the side against Wycombe after suspension and is expected to keep his place after a solid display.