Celtics' Kristaps Porzingis (calf) set for return vs. Knicks - ESPN

Boston Celtics big man Kristaps Porzingis has been upgraded to available for Friday's game against the visiting New York Knicks.

Porzingis sat out the Celtics' past four games because of a low-grade strain in his left calf.

The 28-year-old is averaging 18.9 points, 6.7 rebounds, 1.9 assists and 1.7 blocks in 15 games this season. He is in his first season with Boston after being acquired from the Washington Wizards via trade in June.

Porzingis has averaged 19.6 points, 7.9 rebounds, 1.8 assists and 1.8 blocks in 417 career games (416 starts) with the Knicks, Dallas Mavericks, Wizards and Celtics. He was selected by New York with the fourth overall pick of the 2015 NBA draft.