Boston Celtics power forward Daniel Theis has been ruled out indefinitely after being diagnosed with a slight tear of the plantar fascia in his right foot, according to the team. 

Though he has been ruled out indefinitely, Theis' foot injury doesn't seem to be severe. He'll be re-evaluated in a couple of weeks and the Celtics will likely be cautious with his return.

Theis has seen limited minutes as a reserve this season, but he had a solid showing in Saturday's 109-89 victory over the Detroit Pistons. In 19 minutes of action, the German-born big man racked up 17 points on 7-of-9 shooting from the field (2-of-3 from beyond the arc), eight rebounds, and one assist.

Theis played his way into a key role player for the Celtics last season before suffering a torn meniscus in March. He did not return to action until the preseason this year. Hopefully, this latest setback won't cost him too much time on the sidelines.

Theis, now 26 years of age, made 63 appearances with the Celtics last season, racking up averages of 5.3 points on 54.1 percent shooting from the field (31.0 percent from beyond the arc), 4.3 rebounds, and just under one assist (0.9) in 14.9 minutes per outing.

The Celtics will be back in action on Tuesday night, when they'll welcome the Pistons to TD Garden. Tip-off is set for 7:30 p.m. ET.