It's premature to say that Atlanta changed the series by inserting Al Horford into the flow at center, but the Hawks have given the Celtics something serious to consider.

Horford played 11 regular-season games before tearing a pectoral muscle Jan.?11. He had surgery six days later and didn't play another minute until Game 4 of this first-round series.

He broke out with a 19-point, 11-rebound performance in Atlanta's Game?5 win Tuesday night. Coupled with the reemergence of Marvin Williams as a starter, and Atlanta's move back to its bigger roots, the Celtics are facing a team more closely aligned with the one that took them to seven games in the first round of the 2008 playoffs.