LAS VEGAS - The Celtics announced the signing of Aron Baynes, a key figure in the team’s defensive success last season.

The team didn't disclose the terms but it's a two-year deal worth about $11 million with a player option for the second season.

Baynes, 31, started 67 of 81 regular-season games in his first season with the Celtics, averaging 6.0 points and 5.4 rebounds in 18.3 minutes. He also started 12 of 19 playoff games (6.0 ppg, 6.2 rpg in 20.5 minutes). He anchored the Celtics league-leading defense, which allowed just 97.6 points per 100 possessions with him on the court (third-best among players who played in half of their team’s games).

He also became a surprisingly effective three-point shooter in the playoffs, hitting a team-best 11-for-23 from beyond the arc.

“Aron was a big part of our success this past year and we’re thrilled to have him back,” Celtics president of basketball operations Danny Ainge said in a team release. “He’s a great teammate and an anchor to our defense. The energy and passion that he brings to the table are contagious.”

Jaylen Brown and Jayson Tatum were recently spotted at the Celtics new training facility working out. Baynes was also in the building, working on his improving his body as well for a season in which the expectations will be extremely high for a team that came within a game of getting to the NBA Finals.