Celtics center Aron Baynes has agreed to a two-year, $11 million contract to remain in Boston, according to reports.

The physical interior defender helped Boston finish the 2017-18 season with the league's best defensive rating while owning the best individual defensive rating in the NBA.

The New Zealand-born Australian big man started 67 games for the Celtics while averaging 18.3 minutes per game. The 31-year-old Baynes, who often started alongside Al Horford, will likely take on a reserve role if Boston stays healthy.

Celtics coach Brad Stevens told ESPN that Baynes brings a lot to the table.

"Just his contagiousness. He has, in a lot of ways, just a spirit about him that you want your team to embrace," Stevens said. "His work ethic, his everyday mentality. He brings just a juice every single day. And he's an elite defendant. ... He's a really good player, and he's a really tough guy."

The 6-10 Baynes averaged 6 points and a career-high 5.4 rebounds for the Celtics last season.