Free agent big man Xavier Tillman has agreed on a deal to return to the Boston Celtics, the team announced Tuesday night. 

Terms were not disclosed but sources told ESPN's Adrian Wojnarowski it's a two-year deal. 

Tillman, 25, finished the season with the Celtics after he was acquired in a deadline deal with Memphis to give Boston more frontcourt depth for its stretch run.

It proved to be a wise decision, as Tillman helped fill the hole Kristaps Porzingis' injury left in Boston's playoff rotation. Tillman appeared in eight postseason games -- including two in the NBA Finals -- as the Celtics won a record-setting 18th NBA championship.

In the regular season, Tillman averaged four points in 13.7 minutes for Boston.

The Celtics have prioritized locking in their championship-winning core, handing extensions out to both Jayson Tatum and Derrick White this offseason.

Tillman spent the first four seasons of his career with Memphis after being selected in the second round of the 2020 NBA draft. He was in the final year of a deal he signed before his rookie season.