Memphis, 2-1, will now head to Las Vegas for another handful of games.
Simmons had 10 points, two assists, two steals, and three turnovers on 5-of-10 shooting on Thursday. He played 22 minutes and made his third start.
It was a drop off from the first two games when Simmons scored 21 and 20 points, respectively, on 16-of-31 shooting.
The Grizzlies are back in action Saturday at 6 p.m. PT against the Detroit Pistons
All 30 teams are participating in Las Vegas Summer League, so Deandre Ayton (Suns), Chance Comanche (Magic), Rawle Alkins (Raptors), Allonzo Trier (Knicks), and Kadeem Allen (Celtics) will be making their debuts this week.
Ayton, Comanche, Allen, and Alkins debut Friday. Trier debuts Saturday. The full schedule can be seen here.