Celtics GM Danny Ainge suffered a mild attack Thursday morning, and is currently resting and recovering at Massachusetts General Hospital. It was scary, but he's doing well," Ainge's son, Austin, told FOXSports.com. "We're relieved because all of the tests came back well. We expect him to be up and around in the next day or so. It's under control."

Ainge, who turned 50 last month, suffered the heart attack at roughly 5 a.m. ET while he was sleeping. The team issued a statement Thursday saying that Ainge was "recovering nicely" but is expected to remain at Massachusetts General for a few days.

Ainge was a guard on two of the Celtics championship teams in the 1980s and took charge of the team's basketball operations in 2003. He engineered trades last year for Kevin Garnett and Ray Allen, paving the way for the team to win its first NBA title since 1986.

Ainge missed Wednesday's regular-season finale because he wasn't feeling well and reportedly woke up in the morning with chest pains.