MINNEAPOLIS -- We're back at it with our Countdown to combine series, looking at four positions where the Vikings need help heading into the 2014 draft. It all leads up to our coverage of the NFL scouting combine from Indianapolis.

Position of need: Linebacker

In many ways, this has been a position that's needed upgrading for years. Chad Greenway made the Pro Bowl in 2011 and 2012, but the Vikings' production at middle linebacker has suffered since E.J. Henderson retired, and it became obvious last year they needed a dynamic, playmaking linebacker, as well as a permanent solution in the middle of their defense. It's possible both of those needs could be met in the same player.

Three players the Vikings might be targeting:

Khalil Mack, Buffalo: The 6-foot-3 linebacker has been linked to the Vikings in a number of mock drafts and with good reason; he'd be the kind of athletic linebacker who'd make offenses take notice. As dependable as Greenway has been, the Vikings haven't had a true thumper in their linebacking group for some time. Mack would likely start at weakside linebacker, assuming the Vikings liked what they saw of Audie Cole enough to give him another try in the middle. If Mack played there, he might also give the Vikings some of what they thought they'd get with Desmond Bishop in that spot last year -- a physical linebacker who can rush the passer.

C.J. Mosley, Alabama: If the Vikings were looking for a middle linebacker, Mosley might be their best option. He's particularly strong in pass coverage -- where Erin Henderson flailed at times last year -- and he's got the size to help in the run game, as well. Mosley sustained a nasty knee injury in the 2012 BCS National Championship, and dislocated his elbow last year, but if he shows himself healthy enough to merit first-round consideration, he could get a strong look from the Vikings at No. 8. General manager Rick Spielman has also talked about the possibility of trading back for more picks, and if the Vikings did that, they might still be able to get Mosley at, say, No. 10 or 12.

Anthony Barr, UCLA: He could be gone by the time the Vikings pick at No. 8, particularly if there's a team that sees him being able to bulk up enough to play defensive end in a 4-3 scheme, but he'd be another strong option at outside linebacker. Barr is 6-4 and nearly 250 pounds, so he'd certainly have the size to be an imposing outside linebacker. His best fit could be with a team looking for a 3-4 outside linebacker, but Barr's pass-rushing skills could make him an attractive fit in the Vikings' scheme, as well.