In 2019, Al Horford decided to leave the Boston Celtics in favor of joining the Philadelphia 76ers -- and it had serious repercussions for the Cs (Photo by Maddie Meyer/Getty Images)
The summer of 2019 saw a major shake-up from the Boston Celtics. Of course, Kyrie Irving skipped town to join the Brooklyn Nets. Boston was then able to replace Irving by landing Kemba Walker, luring him away from the Charlotte Hornets. That free agency period also saw the departure of Al Horford — who joined the rival Philadelphia 76ers.
Horford’s exit was a costly one for a handful of reasons.