As the first domino to fall in a line of upcoming contract extensions, Minnesota Vikings linebacker Eric Kendricks set into motion a tricky test for Minnesota's front office to keep the roster together in coming years

Kendricks was the first Viking with a contract due to expire in 2019 to receive an extension. His new deal is worth $50 million over five years with $25 million guaranteed, according to ESPN's Adam Schefter. Pro Football Talk is reporting that Kendricks is to earn $15 million in Year 1, $22.5 million over the first two years, $31.5 million over three years, $40.5 million over four and $50 million over five.

Kendricks, who was to make $1.64 million this season, is now in an elite class of inside linebackers making $10 million or more per season, joining Luke Kuechly ($12.4 million), Bobby Wagner ($10.7 million) and Alec Ogletree ($10.5 million).

The Vikings had $17.8 million in available cap space prior to Kendricks' deal, according to the NFLPA's daily report. With a handful of needs to be addressed in the draft next week, Minnesota shifts focus to the other prominent players scheduled to become free agents after this season: linebacker Anthony Barr, wide receiver Stefon Diggs and defensive end Danielle Hunter. The Vikings also have until May 3 to exercise the fifth-year option on cornerback Trae Waynes' rookie deal.

Getting deals done for all four will be difficult given the Vikings' restraints on future cap space. Kendricks' cap figure in 2018 will be considerably higher than it was before the extension, and though it might not present any issues right now, available spending in 2019 is a completely different story.

General manager Rick Spielman has said the Vikings plan their cap out two years at a time, which is why the franchise felt it was able to give Kirk Cousins a three-year, fully-guaranteed deal worth $84 million. Getting creative with deals in the future will be critical as they work to keep their foundational pieces.

With one of those key defensive pieces in the fold, here's a look at which Viking might be next to receive an extension.

Barr: It makes sense that the Vikings would want to keep their top-tier linebacker duo together for the foreseeable future. Though Kendricks has been more consistent, Barr bounced back last season from an up and down 2016. He displayed the playmaking ability that earned him his first of three straight Pro Bowls in 2015. What kind of deal could Barr command as it relates to Kendricks? It's not often that NFL teams are willing to shell out hefty salaries for multiple linebackers, but given how Barr and Kendricks complement each other in stuffing the run and eliminating dynamic running backs from catching passes out of the backfield, it might be in Minnesota's best interest to keep them together. The Vikings must determine how much value they put on a linebacker, like Barr, who doesn't primarily rush the passer. Minnesota could give him a deal in the range of what Ogletree and Vontaze Burfict earned (about $11 or $12 million per year), and extending Barr now woul allow Minnesota to create $2 to $3 million in cap space depending on how they structure his deal. That's critical in the short term.

Diggs: The kind of extension the Browns gave Jarvis Landry (five years, $75.5 million) could be comparable to what Diggs will command if Minnesota chooses to let him play out the rest of his rookie contract. The benefit in locking up Diggs now, before he has a chance to follow up a fantastic 2017, is getting him at a more reasonable rate -- possibly $11-$13 million per year. Despite missing some time with injuries over the past two seasons, Diggs is one of the Vikings' most valued weapons. The chance to work with Cousins and take his game to the next level might put him in a new tax bracket by the time this season is over, but as CBS Sports' Joel Corry pointed out here, a Diggs extension could complicate things with Adam Thielen (who has a four-year deal worth $19 million) if Minnesota wants to keep internal salary consistency among its receivers based on productivity. For a comparison, the Chiefs gave Sammy Watkins a three-year, $48 million contract last month. Over the past two seasons, Diggs was more productive and both are 24.

Hunter: Pass-rushers get paid a premium, so keeping Hunter will be expensive. That isn't to say he isn't worth the price. The young defensive end exploded for 12.5 sacks in 2016 and followed up last season with seven, proving his worth as an important part of Minnesota's plan for pressuring the quarterback. Hunter could find himself in a situation like DeMarcus Lawrence if the Vikings choose to let him play out the final year of his rookie deal. Lawrence signed a franchise tag with the Cowboys last month with the mindset of playing one year for $17.143 million with an opportunity to "break the bank" in 2019. If Minnesota chooses to let Diggs and Hunter play out their rookie deals, the franchise tag will likely come into play for one of them. Using it on Hunter when it goes up to $18 million or so next season for defensive ends would allow the Vikings to work out a long-term deal by July 2019, which would give them a break on his cap hit. That's important when thinking about the long-term plan for the defensive line, with Everson Griffen scheduled to have a $11.9 million cap hit in 2019.

Waynes: Picking up the former first-round cornerback's fifth-year option has often seemed like a no-brainer. Given what happened with the Bears and Kyle Fuller, Minnesota wouldn't want to find itself in a situation where it had to overpay to keep its starting cornerback because it didn't act sooner. However, the draft could be the determining factor in what the Vikings think about their future with Waynes. If Minnesota drafts a cornerback early and picks up Waynes' option, that would keep the former Michigan State product around for 2019, but after that he might be in position to test the open market.