Since Stiemsma is a restricted free agent, the Celtics  have three days to match Minnesota’s offer. But it is believed the Timberwolves offered more money (reportedly $2.5 million to $3 million per season) than the Celtics have to match (the $1.975 million biannual exception).
Appearing off the bench for Boston last season, Stiemsma averaged 2.9 points and 3.2 rebounds and 13.9 minutes in 55 games.
Stiemsma, 26, was born and raised in neighboring Wisconsin and played at the University of Wisconsin from 2004-08. The Wolves signed Stiemsma to his first NBA contract in April 2010, although he never appeared in a game.
“Minnesota is always where Greg wanted to be,” agent Mike Naiditch told the Star Tribune.
The Celtics apparently have a replacement already, as reports indicate there is a one-year deal in place for veteran center Jason Collins .