DETROIT -- Philadelphia 76ers guard Ben Simmons will miss Monday night's game against Detroit with lower back tightness, after being downgraded from doubtful earlier Tuesday. Philadelphia coach Brett Brown wouldn't rule Simmons out, though, for Wednesday night at Milwaukee.

"He didn't feel as comfortable as we would have wanted," Brown said. "It was just one of those things that with a back-to-back game, we're giving him the best chance we can give him to possibly play tomorrow.

"We felt like it's wise to sit him tonight."

Brown said prior to Tuesday night's game against Detroit that he doesn't believe Simmons' injury will be something the franchise will have to monitor long-term. Simmons, who was the league's Rookie of the Year last season, left Saturday's game against Orlando with a tight back.

Brown did not immediately know who would replace Simmons, who is averaging 12 points, 9.3 rebounds and 7.7 assists this season, in the starting lineup.

With Simmons out, Detroit coach Dwane Casey said he doesn't expect much drop-off because of the depth the Sixers have.

"They still have [Joel] Embiid, they have [Robert] Covington, they have J.J. Redick," Casey said. "It does take away one of their post-up options when he does get a smaller guy on him to go down into the low post.

"But again, it takes away some of their passing. He's one of our best passers in our league and also very cerebral. So any time you lose a guy like that, but again, they don't drop off very much because they do still have some other very fine players."

Casey said Simmons' being out doesn't change much for Detroit, either, other than who would have been guarding him.

Brown also said prior to Tuesday's game that forward/center Mike Muscala will be available Tuesday against Detroit, although he wasn't sure if he would be on some sort of minutes restriction.

"We only just learned that he's available," Brown said. "I assume that comes with some level of restriction. I'm surprised he's playing and I have not gotten more information than that. I suspect there will be parameters, but I have not been told that."