It’s not really a secret that when Al Horford suits up, the Celtics are a much better unit on both ends of the floor and the C’s have been careful with their veteran big man in his 12th NBA season. Horford has been hampered by left knee soreness and sat out three of the last five games – Boston lost all three of those games Horford didn’t play against Charlotte, San Antonio, and most recently, Brooklyn. But at Monday’s morning shootaround, Brad Stevens confirmed that Horford is expected to play tonight against the Miami Heat and most likely won’t have a minutes restriction.