Rondo has a torn ACL in his right knee and will miss the rest of the season.
“Oh my God,” Pierce told ABC’s Doris Burke when she informed him of Rondo’s injury after the Celtics defeated the Heat 100-98 in double overtime.
Pierce sounded and looked like he was hearing the news for the first time.
“We’ve just got to rally around each other,” Pierce said. “I feel for him. He was having such a great season, making the All-Star team. It’s disappointing news. Guys just have to step up.”