Johnson's contract would not have been fully guaranteed had Boston waived him prior to the July 7 deadline, but it instead opted in, which means the 29-year-old veteran will make $12 million during the upcoming season, according to Spotrac.com.
The 2005 second-round pick started a career-high 76 games, averaging 7.3 points, 6.4 rebounds, 1.7 assists and 1.1 blocks while shooting 58.5 percent from the field.
It is unclear if Johnson will remain in a starting role, as the Celtics and former Atlanta Hawks big man Al Horford reportedly agreed to a four-year, $113 million contract, per ESPN.com's Ramona Shelburne.
Horford's arrival will leave Johnson to battle for playing time with Kelly Olynyk and Jonas Jerebko. Tyler Zeller and Jared Sullinger are restricted free agents as well, and it is unclear if the team will bring them back into the fold.
Johnson is limited on the offensive end with a career scoring average of just 7.6 points per game to his credit, but he is a big-bodied player at 6'9" who competes on the boards and is capable of starting or coming off the bench.
He has also been in the NBA since he was 18 years of age, which makes him one of the most experienced players on a Celtics roster that possesses plenty of young talent.
While $12 million is a significant investment in a fringe starter, Johnson is under contract for just one more season, and the short-term investment is worth it for the Celtics as they look to bolster their status as contenders in the Eastern Conference.
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