Watmore impressed on his comeback appearance for Sunderland in midweek, as he scored in the Checkatrade Trophy.
The winger looked like he had never been away, as he helped the Black Cats to a 2-0 win over Notts County.
But Ross does not want to take any chances with Watmore’s fitness and he will be rested tomorrow.
“He won’t be involved on Saturday and then we’ll look at next week,” Ross said.
“He and I speak all the time and we’ve had a plan. So far we’ve stuck to that plan and we’ll continue to do that. By the time we get to the end of the year he should be there but he’s going to have to build it up. I think we’ve done it well so far and we’ll keep that same approach over the coming weeks.”
Sunderland are set to take on Accrington Stanley in League One tomorrow, as they look to continue their fine run of form.
The Black Cats are starting to look assured in their automatic promotion spot, after building up a two point advantage on the chasing pack.
Sunderland also have a game in hand over many of the teams around them, with Ross’ side impressing.
Sunderland could reduce the gap on top of the table Portsmouth down to one point if they win tomorrow.