This offseason of change for the Boston Celtics continued Friday, with Kemba Walker being traded to the Oklahoma City Thunder. 

The Celtics will receive Al Horford, Moses Brown and a second-round draft pick in 2023 from the Thunder in exchange for the four-time All-Star, the No. 16 pick in the 2021 NBA draft and a 2025 second-round pick.

ESPN's Adrian Wojnarowski first reported the deal, also noting the Celtics received some financial flexibility:

It seemed like Boston and Walker were heading for a split after spending the past two seasons together. B/R's Farbod Esnaashari reported June 9 that the two sides were "likely to move forward from their relationship this offseason in a mutual agreement between the parties."

Walker joined the Celtics in July 2019 as part of a sign-and-trade deal with the Charlotte Hornets.

The marriage started out well. Walker was named to the All-Star team after averaging 21.8 points on 38.8 percent three-point shooting and 5.0 assists per game in 46 starts during the season's first half.

Injuries took a toll on Walker down the stretch during the 2019-20 season and continued to linger last season. He shot just 31.0 percent from three during the 2020 postseason.

After undergoing stem cell therapy on his injured knee during the offseason, Walker missed the first 11 games of the 2020-21 campaign. The 31-year-old was able to put together a decent statistical season—19.3 points per game on 36.0 percent three-point shooting—but it was a step down from his best years.

Boston's roster was decimated by injuries during the season, resulting in a 36-36 record in the regular season and a five-game loss to the Brooklyn Nets in the first round of the playoffs.

The Celtics' postseason loss led to an organizational restructuring. Brad Stevens moved into the role of president of basketball operations after Danny Ainge retired. They are still searching for a new head coach. 

Losing Walker does leave Boston with a significant void to fill at point guard, but the roster isn't in dire straits. Jaylen Brown and Jayson Tatum are two of the best young stars in the NBA. Marcus Smart is an excellent defensive player.

Horford knows the Celtics well, having spent three seasons with the organization from 2016 to 2019. He was a key player for their runs to the Eastern Conference finals in 2017 and 2018. The five-time All-Star averaged 13.5 points on 49.8 percent shooting, 7.0 rebounds and 4.6 assists per game in 208 starts with the Celtics. 

The Thunder acquired Horford from the Philadelphia 76ers prior to the start of this season. He appeared in 28 games for the team before being shut down in May. 

There are pieces in place for the Celtics to turn things around quickly, but they need to have a big offseason to realize their potential.

Given where Oklahoma City is at right now, having gone all the way in on rebuilding and acquiring draft picks, it seems doubtful that Walker will play much, if at all, for the team.