Cleveland will sign Perkins on Wednesday, the final day of the regular season, just as it did in 2016 when guard Dahntay Jones was added, and in 2017 when both Jones and center Edy Tavares were added for the Cavs' playoff run.
Perkins was a member of the Cavs team that made the 2015 NBA Finals and was back with them for training camp this fall, before being released during the preseason. He played part of the season for the Canton Charge, the Cavs' G League affiliate.
Perkins, 33, won a championship with the Boston Celtics in 2008 and was part of three other Finals teams in Boston, Oklahoma City and Cleveland.
His last NBA action came during the 2015-16 season, when he averaged 2.8 points and 3.5 rebounds for the New Orleans Pelicans in 37 games.
The Cavs are adding Perkins more for the veteran leadership he can provide to the Cavs' locker room, and less for his on-court contributions, league sources told ESPN.