BOSTON -- Celtics coach Doc Rivers said forward Kevin Garnett bruised his right thigh in a win earlier this month over Memphis and, after Garnett revealed the injury during Monday's practice, Rivers decided to sit him for Tuesday's game against the Pacers.

Rivers didn't make a final decision until spotting Garnett walking uncomfortably in the team's pregame walkthrough Tuesday at TD Garden. Rivers had Garnett and Rasheed Wallace switch spots on the first team for the walkthrough, then informed Garnett shortly before tip-off that he wanted him to sit.

"He wasn't thrilled with it, but I think he's better this year than he was last year," said Rivers. "[Monday], he actually sat down in practice and [Celtics captain] Paul [Pierce] walked over to him and said, 'Wow, someone's growing up.' You know, instead of fighting it.

"He has such a warrior mentality, sometimes it's to his detriment. [Monday], he did a good job. You know he wanted to fight it [Tuesday], and then he just kind of said, 'You're right.'"

Rivers said Garnett got hit in a Dec. 14 win in Memphis, but didn't reveal the injury to trainer Ed Lacerte until a week later at Monday's practice.

Rivers stressed the injury is not related to the surgically repaired right knee and he did not expect Garnett to miss any portion of the upcoming road trip, which starts Christmas Day in Orlando and continues with three games out west.