OTA primer: It's Dalvin Cook's backfield as Vikings ramp up practices

For the first time Tuesday, Vikings’ top pick Dalvin Cook will line up against Linval Joseph and the rest of Mike Zimmer’s defense.

Zimmer won’t be monitoring Organized Team Activities this time, taking a few weeks to recover from the latest surgery to his right eye. But coordinators George Edwards and Pat Shurmur, along with trusted defensive line coach Andre Patterson, will have plenty to evaluate as practices intensify this week.

These voluntary OTA sessions (10 in the next three weeks) are the first of 2017′s practices to resemble actual football. Helmets can be worn. Second-year receiver Laquon Treadwell can now try his hands against Pro Bowl cornerback Xavier Rhodes. And Cook, the heir apparent to Adrian Peterson, can test his knowledge of the playbook in the first 11-on-11 drills.

Still, no pads outside of protective knee and elbow gear are allowed. No live contact is permitted.

The Vikings practice Tuesday, Wednesday and Thursday this week with Wednesday’s session open to reporters. Below are some keys for the Vikings as they begin the most important part of their offseason to date.

Find a rhythm to the run game: Schematic and personnel tweaks to last year’s last-placed running game will finally take shape as Cook, the 41st-overall pick, will start his bid for the Vikings backfield without his biggest competitor. Veteran Latavius Murray isn’t expected to be ready until training camp after undergoing ankle surgery in March. So Cook should get plenty of important reps behind a revamped offensive line. That should give the rookie a solid foundation ahead of the real competition in training camp.

Produce a tentative starting five, build chemistry: Riley Reiff, the Vikings’ $58.75 million man, will take over at left tackle after Matt Kalil’s five years in Minnesota came to an end this offseason. That’s one of four spots you can pencil in along the offensive line with Reiff, left guard Alex Boone, rookie center Pat Elflein and right tackle Mike Remmers. Veteran Joe Berger figures to take the lead at right guard, where he could face a handful of challengers, including Jeremiah Sirles, Danny Isidora and Zac Kerin.

Bring second-year draftees along: Focus will be on this year’s rookies, but don’t forget about last year’s quiet draft class. Treadwell will need to put an injury-marred rookie campaign behind in a crowded receiver room. The Vikings have 12 receivers under contract, all ages 21-27, with veteran Michael Floyd directly competing with Treadwell at split end. Floyd had the remainder of his house arrest transferred from Arizona to Minnesota, allowing him to join the Vikings right away this week. Mackensie Alexander, returning from groin surgery, will also be under the spotlight as he’s tasked with taking over a key role as slot cornerback.

Who’s the leader at defensive tackle?: With Sharrif Floyd’s long-term playing future uncertain, the Vikings brought in former Packers defender Datone Jones, drafted Iowa’s Jaleel Johnson and could even return Pro Bowl end Everson Griffen to his interior pass rush role with the emergence of Danielle Hunter at end. The Vikings have a supremely talented defensive line, but they may have to make do without a former first-round pick.

Sharpen the backup quarterbacks: As Teddy Bridgewater continues his long road in recovery, the backup job behind Sam Bradford is an open competition between third-year passer Taylor Heinicke and free-agent addition Case Keenum. Either can get a foothold on the job ahead of training camp with how they throw in the next few weeks.

Get a read on specialists: The exit of Cordarrelle Patterson will be missed most in the return game. Fifth-round receiver Rodney Adams may be the leader in the locker room with veteran punt returner Marcus Sherels a solid fallback option for coordinator Mike Priefer. Competitions at punter and kicker will also continue with both Blair Walsh and Jeff Locke on different teams. Kai Forbath will try to ward off Marshall Koehn and veteran punter Ryan Quigley gets another shot to stick in the NFL against the young Taylor Symmank.