Dons have options to replace suspended Morris
The striker received a straight red card for downing John Marquis late in the day during Dons' 3-1 defeat to Portsmouth on Tuesday night, ruling him out of a return to the club he began the season on loan to.
Morris has helped transform Dons since his arrival from Norwich in early January, but his suspension means Martin will have to shake up his attack to replace him at Rotherham.
He said: "We've got loads of options – Carlton brings so much. He'll be a huge loss for us, no doubt about it, but we've got options. We've got Sam, Rhys, Joe Mason is back fit again now, Ben Reeves, Ben Gladwin too. We've been discussing all the options since Tuesday, but we have options.
"We have to decide how we go about beating Rotherham. If we have to tweak the system, we'll have to do that, but whoever comes in, I trust them."
Injury to Joe Mason has ruled him out for the last month, but Martin confirmed he is back in full-time training and could feature at the New York Stadium,
"It's great to have Joe again," he said. "He's a top player at this level, so we have to keep him fit. It's nice to have him back in the squad and involved. He could be a big player for us."
And after missing the two away games against Shrewsbury and Lincoln, Ben Gladwin also made his return to first team action with substitute appearances against Bolton and Portsmouth - the latter of which he impressed during the final half an hour.
Martin added: "He's getting better and better. He's getting more and more minutes too. If he carries on what he's doing, and the quicker we can get him into a position where he can start a game the better.
"He came on and was running the game in the last 15 minutes. We have to keep him fit and get him ready, and you can see in him he's feeling more confident in his body."