Who should the Celtics target for their front court?

Brad Penner-USA TODAY SportsWith Amir Johnson, Jonas Jerebko, and potentially Tyler Zeller entering free agency, Kelly Olynyk due a qualifying offer, and Ante Zizic and Guerschon Yabusele waiting in the wings, what other big men should the Celtics go after this summer?

Keith Smith: My favorite target for the Celtics is Alan Williams. Williams is a restricted free agent with the Phoenix Suns. The Suns would probably pause at matching offers that start in the $8-10 million average annual value range. Williams is a bit undersized, but plays bigger than his measurements. His Per 36 minute numbers last year were 17.6 points per game on 52 percent shooting, 14.8 rebounds per game and 1.6 blocks…