CLEVELAND — One year ago, David Griffin celebrated the biggest win in Cavaliers history.

He marked the anniversary Monday by walking away from the team.

Griffin’s three-year run as general manager with Cleveland is over after one championship and three straight trips to the NBA Finals.

After guiding the team through its most successful stretch, Griffin mutually parted ways with the Cavs as owner Dan Gilbert said the GM’s contract will not be extended once it expires June 30.

“On behalf of the entire organization, I would like to thank Griff for his leadership and many contributions during his time here, including most recently, his role in the franchise’s first NBA Championship,” Gilbert said in a statement. “We have no announcement at this time related to new leadership of the Cavaliers basketball operations group, but we are confident our current front office will continue to aggressively explore and pursue opportunities to improve our team in the weeks ahead.”

Griffin’s departure comes on the one-year anniversary of the Cavs’ dramatic Game 7 win over Golden State, capping a historic comeback that gave Cleveland its first major professional sports championship since 1964.

He’s also leaving three days before the draft and on the eve of free agency. Cleveland could have a busy summer as it looks to revamp its roster after losing to the Warriors in five games in this year’s Finals.

With Griffin out, the Cavs enter a critical juncture without a seasoned executive making the calls. The Cavs will try to improve their roster this summer as superstar LeBron James enters his final season under contract.

A team spokesman said Trent Redden, the team’s senior vice president of basketball operations, is also not returning.