New Boston Celtics big man Tristan Thompson played with LeBron James on the Cleveland Cavaliers for four years. The Cavs went to four straight Finals from 2014-2018 and won the 2016 championship over the Golden State Warriors in seven games, becoming the first team in NBA history to erase a 3-1 series deficit in the Finals.

Since Thompson learned so much about the game of basketball and what leadership is all about from James, he plans to bring those lessons with him to the Celtics.

“It was a once in a lifetime opportunity to be part of that, so for me to be able to share my wisdom from what I learned from LeBron James and pass on to these guys is what the NBA is about,” Tristan Thompson told Celtics reporters on Thursday, via Mass Live.

“Never be afraid to speak up. If you see something that’s not right, you have earned the right with this ballclub to speak up and say your mind. If you are the guy that punches the clock and does the right things everyday, you’ve earned the right to light a fire under your teammates’ ass or call them out because we all expect the best from each other.”

Thompson, one of the best rebounders in the NBA, signed a two-year, $18.9 million contract with the Celtics in free agency. He will start alongside Kemba Walker, Jayson Tatum, Jaylen Brown and Marcus Smart, though Walker will miss the start of the upcoming season due to his knee injury.

The Celtics lost to the Miami Heat in the 2020 Eastern Conference Finals in six games at Walt Disney World in the NBA bubble. Thompson will help Boston on the boards and is a solid rim-roller in the pick-and-roll game. He averaged 12.0 points and 10.1 rebounds per game for the Cavs last season.