I'm not worried about IT getting his, even in the playoffs. The spacing on the floor is much better this year so long as Bradley, Crowder, and Horford are healthy.
My concerns would be:
(a) Preventing bigger guards from roasting us alive. Derozan, Lowry, Dragic, Waiters, TJ, Wall, Beal ... there are plenty of guys in the East that can give this team problems.
(b) Getting beasted on the boards. While the Cavs, Raps, and Wizards aren't great rebounding teams by the overall numbers, they have players that can give the Celts problems. Gortat, Thompson, Valanciunas, etc, not to mention bigger wings (Bron, Tucker, Carroll, Porter, Oubre, etc). Then there are the teams lower in the bracket -- the Bucks are huge, the Hawks have Dwight, and the Heat have Whiteside.