Sources - Celtics' Kristaps Porzingis could return by Game 4 - ESPN

There's growing optimism that Boston Celtics center Kristaps Porzingis could make his return to these Eastern Conference playoffs against the Indiana Pacers as soon as Game 4 on Monday, sources told ESPN.

Porzingis has been making progress from a soleus strain of his right calf, accelerating his on-court ramp up and increasing his fitness to make his conference finals debut possible once the best-of-seven series returns to Indianapolis, sources said.

Porzingis — out since suffering the injury in Game 4 against the Miami Heat on April 30 — missed the entirety of a five-game conference semifinals series victory over Cleveland and will miss the opening of these conference finals in Boston on Tuesday night.

The Celtics won't rush Porzingis back and want to continue to be conservative in his recovery, but sources say he is inching closer to a return.

Porzingis was a major offseason addition to the Celtics, bringing with him an immense impact on both ends of the floor for the best regular-season team in the league. At 7-foot-3, Porzingis averaged 20 points and 7.2 rebounds — including holding opponents to 44.3% in the paint, which was an NBA-best among contesting defenders of 500 shots or more, per Second Spectrum.

Porzingis arrived in a three-team offseason trade with Washington and Memphis.