Center Kristaps Porzingis takes a 3-point shot during the Celtics’ 126-94 win over the Clippers on Monday in Boston. Porzingis scored 16 points and grabbed six rebounds in his first game this season. Charles Krupa/Associated Press

BOSTON — Kristaps Porzingis was a spectator for the first month of the NBA season following offseason ankle surgery.

It didn’t take him long during his season debut against the Los Angeles Clippers on Monday night to remind his Boston Celtics teammates what they’ve been missing.

Late in the second half, the Clippers were on offense when Kris Dunn drove the baseline and went up for a dunk. He was met at the rim by the outstretched arms of the 7-foot-2 Latvian, who sent it back to the floor with a two-handed block.

A few trips later, Porzingis showed off that length on the offensive end, catching an alley-oop from teammate Jaylen Brown that garnered roaring approval from the TD Garden crowd.

“It was a good beginning. Good first game back,” Porzingis said.

He finished with 16 points, six rebounds and two blocks over 23 minutes in Boston’s 126-94 win over the Clippers.

It was Porzingis’ first game action since undergoing left ankle surgery in June to fix a tear in the tissue that holds the ankle tendons in place.

He said he actually started to feel game ready about a month ago.

“I was always asking the medical staff to do more,” Porzingis said. “But we were really smart and completed all of the stages to get to this point.”

Porzingis’ teammates got him involved early, going to him on each of their first two possessions. Porzingis fired up a 3-pointer from the wing on Boston’s offensive touch, then drained one from the top of the key on the Celtics’ next trip up the floor.

He played nearly seven minutes of the first quarter, relieved at the 5:12 mark by Neemias Queta.

Boston is 15-3 this season, but has missed his presence on the inside, with teams routinely outscoring the defending champions in the paint.

Coach Joe Mazzulla acknowledged that how Porzingis plays on the offensive end, particularly how he operates sometimes out of the high and low post, will force some adjustment from how the team has played this season without him on the floor. But he was most pleased with what he added on the defensive end, where he helped everyone rally around the ball.

“We had 11 blocks tonight. It helps,” Mazzulla said.

The original window for Porzingis’ return following surgery was five to six months. But Celtics President of Basketball Operations Brad Stevens said before the season that they didn’t want to hold to a specific timeline because of the uniqueness of the injury.

“We got here maybe a month early,” Porzingis said. “Honestly, I felt better than I expected.”

Porzingis injured his ankle in Game 2 of the NBA Finals against the Dallas Mavericks and missed the next two games. He returned for Game 5, contributing five points and one rebound in 16 minutes as the Celtics beat Dallas 106-88 to clinch their record 18th title.

“To have big fella back, it makes us complete,” Celtics teammate Payton Pritchard said.