"He's going to try to give it a go," Celtics coach Brad Stevens said.
Stevens said Horford told the team he felt sick Tuesday night. The coach said they were worried it was a 24- to 48-hour thing, but Horford said Wednesday morning he was feeling better.
He was not at shootaround, but arrived Wednesday night determined to play in Game 2 of the series at TD Garden.
Horford had 10 points, 11 rebounds and 5 assists in Boston's Game 1 win on Sunday.