The Magic lost a high-scoring guard in Cuttino Mobley and the Celtics found one in rookie Tony Allen.
Allen scored 16 in 20 minutes in a 119-101 win Monday night against a team shaken by the trade that sent Mobley to Sacramento shortly before the game.
Steve Francis, Mobley's close friend, appeared distracted on the court and was upset afterward.
"For us, not just myself but everybody, we were pretty much just emotionally drained," Francis said. "You don't wait 30 minutes before a game to tell a guy he's traded."
Coach Johnny Davis said he learned a few minutes before the game that the trade had been completed, bringing Doug Christie to the Magic and also sending forward Michael Bradley to the Kings.
"We felt that Doug was a perfect fit for the chemistry of our team," Magic general manager John Weisbrod said in a statement. "He's a tremendous passer and defender, he's accustomed to playing in an up-tempo offense and he brings valuable playoff experience."
Mobley, who could become a free agent after the season, was Orlando's third-leading scorer with 16 points per game.
Standing near the team's locker room during the second half, Mobley said, "I'm sad. Maybe (the Magic was) scared I wouldn't sign back."
Francis had 18 points but played just 27 minutes. He and Mobley had joined the Magic in an offseason trade that sent Tracy McGrady to Houston. Several Orlando players wore black armbands with Mobley's No. 5 on them.
"It was hard for me to play. He is my brother," Francis said. "I've played my whole career with him."