Simms has scored three goals in the Championship since joining Sunderland on loan from Everton in the summer transfer window.
However, the forward sustained an injury in Sunderland’s 3-0 win over Reading earlier this week and there were fears that he could be missing for a lengthy period of time.
While the injury was not as serious as feared, Simms is still a major doubt for Sunderland’s trip to Watford on Saturday.
Mowbray stressed that he is still hopeful about the forward’s involvement on Saturday but it will depend on how he feels in training today.
He pointed out that the worst-case scenario is that he misses Saturday’s game and will have two weeks to recover for the fixtures after the international break.
Asked about Simms’ injury, the Sunderland boss said in a press conference: “We’re hoping he’s going to be okay.
“He’ll have a jog about on the grass today and we’ll wait and see.
“Worst comes to worst, we’ve got two weeks after tomorrow and I’m sure he’ll be fine after that.”
Sunderland have made a strong start to the season following getting promotion and are sixth in the Championship standings.
