When Brad Stevens traded Kemba Walker to the Oklahoma City Thunder for Al Horford and Moses Brown, a lot of people raised their eyebrows. After all, the Boston Celtics parted ways with an All-Star caliber guard for a 35-year-old player they let walk away a couple of seasons ago.

However, Stevens has a good reason for doing so aside from the financial flexibility it gives them. According to the Celtics' new president of basketball operations, having Horford back gives them a player who “can move the needle” in a way that Walker wasn't able to do during his two years in Beantown.

“Al can move the needle,” Stevens said of the trade, per Jared Greenspan of the New York Post. “… I think that sometimes the ability to space, pass, play in different ways and play in different coverages at the other end, be able to play with other bigs or as the lone 5 I think is something that … he just has a wealth of experience.”

Brad Stevens was able to coach Al Horford in his three-year stay in Boston before he moved to the Philadelphia 76ers in 2019. During those years, the veteran big man averaged 13.5 points, 7.0 rebounds, 4.6 assists and 1.2 blocks in 208 games–all starts. He was an effective player under Stevens, so it wasn't surprising when the ex-Butler tactician made a move to bring him back.

It is also worth mentioning that there were reports claiming that Stevens and Kemba Walker didn't have the best relationship. According to rumors, Stevens was particularly hard on Kemba and they began to butt heads amid the dysfunction in the locker room.

Now that Kemba is out of Boston and Al is back, hopes are high the Celtics can move on from their forgettable 2020-21 season and build a contender as they usher into a new era under Stevens.