Raphinha sat down on the Elland Road pitch late on against Chelsea and appeared to be stretching out his right leg. Marsch said after the game the Brazilian's withdrawal was precautionary because he was cramping up. Harrison took a knock from Reece James early on and failed to run it off, Junior Firpo replacing him on 37 minutes.
Head coach Jesse Marsch says both men should be involved this weekend.
"Jack Harrison with the contusion looks positive, he should be in training tomorrow and ready to go," said the American.
"Rapha is fine and ready to go."
Patrick Bamford has been fighting to get fit and while Marsch was expecting the centre forward back in training this week, he's not yet able to say if the Brighton game will bring about his comeback.
"It's a bit too early to see where he's at, we'll evaluate it over the next few days," he said.
"I don't want to say too much about Patrick right now, let's just see. I want to give him the oppy to continue to progress and then make a decision on his involvement in each match. Everybody is working together, our medical team, Patrick, us as a coaching staff to evaluate where he's at."
Leeds are without the suspended Luke Ayling and Daniel James for their final two games, along with Stuart Dallas [femoral fracture], Adam Forshaw [fractured kneecap], Tyler Roberts [torn hamstring] and Crysencio Summerville [ankle].