Horford is a key member of Joe Mazzulla's roster. Not only is he a reliable presence on the court, he's also a leader in the locker room and on the bench. Nevertheless, Horford may value the opportunity to keep contending for a championship next season, which is something Boston is unable to offer.

So far this summer, the Warriors have seen one of their own longtime centers, Kevon Looney, abandon the team for the New Orleans Pelicans in free agency. It's not a great loss, as Looney proved virtually unplayable in the postseason.

Entering NBA free agency, the expectation was that Al Horford would land with the Golden State Warriors and not return to the Boston Celtics. While Horford has not yet formally agreed to a contract to join the Warriors,