The Millers rejected a £100,000 offer from Crawley Town for Grabban this month and have fielded enquiries from other League Two clubs.
“We have had dialogue with a couple of clubs but I have spoken to Lewis and the chairman and we are of the same opinion,” said Scott.
“If Lewis finishes the season as he started it, he will end up with 25 goals and there will be Championship and top League One clubs in for him this summer. At that stage, we would have a struggle.”
Scott, meanwhile, slammed the attitude of fringe players who have rejected opportunities to leave on loan.
“As a player, I wasn’t prepared to sit around picking money up for doing nothing,” he said. “I am going to make sure they work for their money.
“If they don’t get a club at the end of the season, they will have no-one to blame but themselves.”
Striker Chris Holroyd is heading to Preston.