The 23rd team in this 32-part series for Yahoo! Sports. Check out the entire piece on this link.There's little doubt that the Indianapolis Colts were the surprise team of the 2012 NFL season. Chuck Pagano's squad went from two wins in 2011 to 11 victories and a playoff berth a year ago.But let's not forget the quantum leap that the Minnesota Vikings made last season. One year after finishing 3-13 (tied for the most losses in a season in franchise history), the Purple Gang won 10 games and grabbed a wild-card invitation.Is Leslie Frazier's club capable of bigger and better things? Well, we're now on to 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 Minnesota Vikings: