Al Horford tweets he's leaving The Hawks

Al Horford is leaving the Atlanta Hawks. The forward announced on Twitter he is joining the Boston Celtics.

Multiple reports say the it will be a four-year deal for $113-million.

Horford spent the last nine seasons playing for the Hawks. He made the All-Star team four times. Atlanta drafted him in the first round of the 2007 Draft out of the University of Florida.

The Hawks have been busy in free agency, re-signing free agent forward Kent Bazemore and signing Atlanta-native Dwight Howard.