So far for the Boston Celtics, the offseason has been mostly about subtraction. But Brad Stevens has signed two depth players so far in free agency.

The Celtics signed the former Minnesota Timberwolves center to a two-year, $5.5 million, fully guaranteed contract fresh on the heels of losing backup big man Luke Kornet to the San Antonio Spurs and a four-season,

The Celtics have made their first move of free agency on Monday night, agreeing to terms with former Wolves big man Luka Garza, a source tells MassLive. The deal with Boston is a two-year pact for the veteran’s minimum. ESPN was first to offer the deal.