The former AFC Wimbledon hitman came off the bench to net a last-minute consolation in the 3-1 defeat Burton and the 25-year-old will be hoping to get the nod to face the Millers.
Jermaine McGlashan was introduced at half-time along with Harrison and the winger is also pushing for a start.
Manager Mark Yates has no fresh injury worries with defender Harry Hooman their only absentee for the clash against a side level on points with the Robins in npower League Two.
But Yates will not be able to name Jason Taylor in the squad against his former employees due to a gentleman's agreement between the two clubs when the midfielder moved to Cheltenham in the January transfer window.
The defeat to Burton last time out was Cheltenham`s first defeat in seven games and they remain three points off the automatic promotion places.