BOSTON -- You don't have to tell Scott Brooks what Isaiah Thomas means to the Boston Celtics. He witnessed it first-hand.
The Wizards coach took the Washington job at the beginning of the 2016-17 season. Celtics fans know what happened that season: Thomas averaged a career-best 28.9 points per game and dazzled in the playoffs, knocking Brooks' Wizards out of the second round of the playoffs with a historic seven-game stretch that included a 53-point outburst in Game 2.
The Celtics traded Thomas in the 2017 offseason but remained a legitimate Eastern Conference contender. Brooks believes that's a credit to Thomas, who established Boston as a team to be reckoned with during his two-plus seasons with the team.
"I.T. started this run where they've had basically five years of being one of the best teams in the league," Brooks told reporters Wednesday night before Thomas' return to TD Garden to face the Celtics. "Unfortunately they haven't taken that next step, but this is another year that they're going to be one of the best teams and have a chance to win it all.
" ... But I.T., I think he started it. When they made that trade [with] Phoenix, this team was changed, and this franchise changed because of that."
"That trade" was a Danny Ainge special, in which the Celtics president of basketball operations sent Marcus Thornton and a 2016 first-round pick to the Suns in February 2015 for Thomas, then a productive but relatively unheralded point guard.
Thomas became very much heralded in Boston, making two consecutive All-Star teams before a hip injury derailed his career.
The 30-year-old is staging a comeback with Washington, though, averaging 13.2 points through six games and taking over as the Wizards' starting point guard over the team's last three games.
Brooks, like Thomas' former head coach and teammates, isn't betting against him.
"Nobody in the league knew he was an All-Star other than himself and his family," Brooks said. "And that was a long time ago. He got there because of his work and his toughness and his ability to compete at a high level every night against the best players. He wants it all."
Don’t miss NBC Sports Boston's coverage of Celtics-Warriors, which tips off Friday at 9:30 p.m. ET with Celtics Pregame Live, and then Mike & Scal have the call of the game at 10:30 p.m. You can also stream the game through the MyTeams App.