Dallas Mavericks forward Cooper Flagg attacked the rim against the Boston Celtics but landed awkwardly on his left foot before falling to the floor.

Flagg immediately grabbed his left foot in visible pain. He had just returned from an eight-game absence with a left midfoot sprain. Flagg hobbled to the bench as Mavericks coach Jason Kidd called a timeout so he could be evaluated.

After the timeout, however, Flagg limped to the free-throw line and remained in the game.

He did not appear to labor on the foot for the rest of the night and played 30 minutes, which is his highest total since returning from the injury. But Flagg wasn’t the only star returning from an injury.

Boston Celtics forward Jayson Tatum — whom Flagg said before the draft he studied before entering the NBA — returned after tearing his Achilles last season. Tatum missed about 10 months with the injury.

He finished with 15 points, 12 rebounds and seven assists in Boston’s 120-100 win over the Mavericks at TD Garden on Friday night.

The Mavericks have now lost six straight games.

Flagg struggled from the field, shooting 7-of-23 (30 percent) for the second consecutive game as he continues to work his way back from the extended absence. He also had eight rebounds and six assists.

Mavericks guard Klay Thompson scored 19 points, including five 3-pointers. It was the second straight game he has made at least five 3-pointers. Thompson’s floor spacing helped Dallas keep the game within 10 points through the first three quarters.

Thompson is second in the NBA with 152 3-pointers off the bench, trailing only former Mavericks guard Tim Hardaway Jr.

Mavericks guard Max Christie scored 12 points, including four made baskets from beyond the arc.