Al Horford reportedly headed to Sixers

Al Horford Boston Celtics NBA
The Celtics were left without a big man after Al Horford agreed to a 4-year, $109 million deal with the Sixers. –Barry Chin/Globe Staff

Celtics forward Al Horford has agreed to a four-year, $109 million contract with the Philadelphia 76ers, according to ESPN.

The acquisition gives a major boost to one of the Celtics’ top rivals after it lost Jimmy Butler to the Heat. According to a league source, Horford planned to speak with several teams Sunday night and then make a final decision Monday or Tuesday. But that process might have accelerated after Butler’s departure in Philadelphia offered some clarity.

Horford apparently wanted out of Boston because he wanted a four-year deal (the Celtics offered one late) and he no longer wanted to play center, a position that exhausts him. He’ll be paired with the best and biggest center in the NBA in Joel Embiid, so that will no longer be an issue.