BRISTOL, Conn. -- The Minnesota Vikings began their offseason workout program with just five linebackers under contract for the 2017 season.

The group is young enough (only Emmanuel Lamur is over 25) and familiar enough with Mike Zimmer's system (Lamur's final two years in Cincinnati were the only NFL seasons any of the linebackers have played apart from the coach) that it's conceivable the Vikings would only add another player or two for depth. But things might not be so simple.

Chad Greenway's retirement at age 34 means the group will have a new leader in 2017; even though Greenway's role had diminished in recent years, he still established the standard for how the Vikings' young linebackers would approach their jobs. And the highest-drafted player the Vikings have selected in the Zimmer years is headed toward a critical season.

Anthony Barr had just two sacks, a forced fumble and a fumble recovery for the Vikings in 2016. AP Photo/Paul Sancya

Anthony Barr, who was selected ninth overall in 2014, will learn of the Vikings' decision on his fifth-year option by early May. And even if the Vikings pick up Barr's option -- at the transition tag amount of more than $12 million -- they could still cut him before the start of the 2018 season. He had just two sacks, a forced fumble and a fumble recovery during a puzzling third season in Minnesota, and he'll need a forceful showing in Year 4 if he's going to be around for the foreseeable future.

Eric Kendricks will anchor the group after an impressive second season in Minnesota, but the Vikings will need to figure out who takes Greenway's spot at weak-side linebacker in the base defense. And they'll have to see if they can expect more from Barr.

Current LBs (2017 cap number in parentheses): Barr ($4.055 million), Lamur ($2.75 million), Kendricks ($1.406 million), Edmond Robinson ($632,078), Kentrell Brothers ($598,170).

Player with most to prove in 2017: Zimmer's comments about Barr toward the end of last season -- that the linebacker could do a lot better in all areas of his game, and that he had a tendency to coast at times -- were particularly incisive because of where it seemed Barr stood with the team before the 2016 campaign. He wasn't making the kind of big plays (sacks, forced fumbles and interceptions) the Vikings had come to expect from him after a Pro Bowl 2015 season, and he didn't spend enough time on the Vikings' injury report to suggest he was playing through a serious ailment. If he becomes a more effective pass-rusher and is a sturdy option in coverage, he could lead the Vikings to consider a contract extension for him. Otherwise, Barr could find himself in limbo after this season.

Draft need: The Vikings likely will give the first shot at Greenway's old spot to Lamur or Robinson, and Brothers built some momentum for himself with a solid special teams showing as a rookie. Another player who can compete for playing time and help out on special teams would be a logical investment in the middle rounds of the draft, and the Vikings have spent some time with Kansas State's Elijah Lee, who could work at a number of spots in the NFL.