Training camp preview: Buffalo Bills

After plenty of changes in the offseason, the Buffalo Bills will take the field for the first time in training camp on Sunday. The Bills are the last team to practice this year in the AFC East.

Buffalo is a major team in transition in 2013. The Bills have a new head coach, a new offensive coordinator, a new defensive coordinator and a new quarterback. Therefore, there is plenty of work to be done.

Here are three things to watch in camp:

No. 1: QBs Kevin Kolb vs. EJ Manuel

Analysis: All eyes will be on the quarterbacks in Buffalo. The Bills are entering training camp with a high-profile competition between veteran quarterback Kevin Kolb and rookie first-round pick EJ Manuel. Kolb has been a bust in his two previous stops with the Philadelphia Eagles and Arizona Cardinals. This third opportunity in Buffalo is probably Kolb’s final chance to prove that he can be a franchise starter. Manuel was a surprise first-round pick but has a lot of tools, such as size, a good arm and mobility. But Manuel remains raw and will have to make immediate strides in order to win the starting job in Week 1.

No. 2: Mike Pettine’s defense

Analysis: Buffalo's defense had talent last year but grossly underperformed. Former defensive coordinator Dave Wannstedt got most of the blame, and he was fired after the season. Enter former New York Jets defensive coordinator Mike Pettine. He was hired new Bills head coach Doug Marrone to liven up Buffalo's defense. Pettine usually got the most out of his defensive players in New York, and that will be the goal in Buffalo. Players like Mario Williams, Stephon Gilmore, Kyle Williams and Jairus Byrd (whenever he signs his franchise tag) provides a good foundation on defense. But it's Pettine’s job in training camp to get everyone on the same page.

No. 3: Competition at WR

Analysis: For years, the Bills have been looking for another legit receiving threat opposite Steve Johnson. That search continues this season with an entirely new cast of receivers, many of which are rookies. The Bills drafted second-round pick Robert Woods, third-round pick Marquise Goodwin and signed top rookie free agent Da'Rick Rogers in an effort to boost depth behind Johnson. Woods, a former USC star, has been the most polished receiver thus far. He's the favorite to win the No. 2 job but must earn it in training camp. Goodwin has plenty of speed and could add a deep element to Buffalo, and Rogers also has potential to contribute if he stays out of trouble. Rogers was passed over by every team in the draft due to various off-the-field concerns.