The fourth part of our 32-team preview on Yahoo! SportsGive the Philadelphia Eagles a "D" over the last two seasons.The D could have stood for dream team. And wasn't there the mention of a dynasty?Try disaster. Following a disappointing 8-8 finish in 2011 in which the team had to win its final four games to get to the .500 mark, the Birds fell to 4-12 a year ago. That was following a 3-1 start which included wins over the eventual Super Bowl champion Baltimore Ravens and defending Super Bowl champion New York Giants. But four victories doesn't cut it anywhere and head coach Andy Reid was let go after 14 seasons with the team. Former University of Oregon head coach Chip Kelly now looks to guide the franchise to its first NFL title since 1960.Hence, it is onto 2013 and here we will take a look at five players who could be critical to the team's success this upcoming season. While in some cases the obvious will be stated, in other instances the focus will be on a newcomer to the team or a performer looking to rebound from a disappointing year. So here are five players to keep an eye on this season when it comes to the Philadelphia Eagles: