Rams face neighbours Batley Bulldogs at the Summer Bash in Blackpool on Sunday and could be without second-rowers Scott Hale and Kyle Trout.
Coach Glenn Morrison said Hale suffered damage to an elbow and Trout went off with a knee problem. Rams also had centre Jason Crookes and prop Luke Adamson sin-binned at different times in the first half of the weekend encounter with Rovers.
Crookes was banished for a high tackle and Adamson went off for 10 minutes following a team warning.
“It was a tough one,” Morrison admitted of the defeat which left Rams eighth in the table.
“The scoreline didn’t really reflect the effort we put in.
“The boys tried hard and, defensively, we were pretty solid – especially being a man down for a lot of the first half.
“But with the ball we were nowhere near good enough.
“In the second half we completed at 40 per cent and I think that was down to frustration about things that were not in our hands.
“We were pretty disappointed with some calls.
“They [Rovers] were too good, but we weren’t really given an even chance to play.”