Celtics sign Al Horford to contract extension

The Boston Celtics have signed center Al Horford to a contract extension. Per the Boston Herald, “the C's did not disclose terms of the deal, but according to multiple reports, it's a two-year, $20 million extension that will keep Horford in Boston through the 2024-25 season, when he turns 39. The center's $26.5 million salary …