The Senior Bowl is under way in Mobile, Ala. this week. It's an event that comes and goes without much fanfare, but for NFL teams it's an important part of the offseason as they look for players who can help improve their rosters.

Evaluating the incoming class of draft-eligible players is about more than looking at the Heisman Trophy candidates and the award winners. The Senior Bowl is a good reminder of that because there aren't always a lot of future first-round picks walking around Mobile, but there are always a lot of future stars who participate in Senior Bowl week.

Sometimes teams have to dig deep to find those players who have the right characteristics and traits but still need plenty of polishing. Look no further than the Vikings work with the defensive line of late. Head coach Mike Zimmer, defensive coordinator George Edwards, defensive line coach Andre Patterson and assistant defensive line coach Robert Rodriguez deserve a lot of credit for the work they've done with the defensive line. The Vikings scouting staff also deserves credit for having found these unheralded college players with middle-round and late-round picks.

Here's a quick look at three of them:

Everson Griffen: He was selected by the Vikings in the fourth round of the 2010 draft and generated 23.0 tackles for loss, 17.0 sacks and 67 quarterback hits in his first four seasons as a reserve. Zimmer's first year on the job in Minnesota was Griffen's first year as a starter, and it was the beginning of a big move up for Griffen. Since Zimmer's arrival (three seasons), Griffen has tallied 48.0 tackles for loss, 214 quarterback hits and 30.5 sacks in 47 games.

Danielle Hunter: He was selected with a third-round pick in 2015 and with tutelage from the Vikings coaching staff he has doubled his production year-over-year, going from 6.0 sacks, 34 tackles and 25 quarterback hits as a 2015 rookie to 12.5 sacks (team best), 64 tackles and 49 quarterback hits in '16.

Shamar Stephen: There aren't a lot of former seventh-round picks who are now starters walking around, but the Vikings have one in Stephen. In his third season, Stephen, a 2014 Senior Bowl alumnus, earned a starting role on the Vikings defense heading into 2016 and was huge for the team because 2013 first-rounder Sharrif Floyd was sidelined for 15 games. They call Stephen the big fundamental because of his sharp technique and consistency in making the routine plays.

So what's the moral of the story? It's that the defensive coaching staff has done a great job with developmental defensive lineman and it would make sense to continue giving that crew talent to mold.

One way to generate improvement is to strengthen areas of weakness. This is why many will focus on offensive linemen when they analyze the Vikings at events such as the Senior Bowl. Another way to generate improvement is to fortify areas that are already strong. From this standpoint, it will be interesting to see if the Vikings spend a 2017 draft pick on a defensive lineman who could be molded by Zimmer and his accomplished, well-respected staff.

That draft pick may be in Mobile right now, which makes following the Senior Bowl this week that much more important for Vikings fans.