The Vikings began full-squad training camp Friday with five players sidelined, including two key defenders in cornerback Mike Hughes and defensive tackle Shamar Stephen.

Hughes was among three players placed on the physically-unable-to-perform (PUP) list. He will count against the 90-man roster limit, but will not be able to practice with the team until medically cleared.

Coach Mike Zimmer revealed Friday that Hughes is actually recovering from a "multi-ligament" knee injury, not just the ACL tear Zimmer said Hughes suffered Oct. 14 against Arizona.

"He's ahead of schedule. He's doing great," Zimmer said. "So we just have to see where it goes. Some of them will be short term and we'll just have to see where it goes."

Zimmer did not elaborate on Hughes' knee damage.

"I'm not smart enough to know all those things," Zimmer said. "I know he had an ACL and then he had something else."

Tight end David Morgan and receiver Brandon Zylstra were also placed on the PUP list. Zylstra is dealing with a left hamstring issue, according to a source. Morgan, the blocking tight end who was unable to practice this spring, missed three games at the end of last season because of a knee injury.

Stephen (undisclosed) and defensive lineman Tashawn Bower were placed on the active/non-football injury list.

Stephen, who is expected to start next to Linval Joseph, is "not going to be out long," per Zimmer. Bower tore his Achilles' tendon while working out on his own.

Kicking tires on DBs

Cornerback depth is an early concern for the Vikings after Holton Hill was suspended or eight games and Hughes recovers from his injury. So the team worked out another potential veteran addition Friday in Mo Claiborne, the former Cowboys first-round pick, a league source confirmed.

Zimmer alluded to the possibility of signing more cornerback depth during training camp when asked about Hill, adding "disappointed is not a good word for me."

The Vikings also worked out veteran cornerback Orlando Scandrick on Wednesday.

"We don't know if [Hill] is even going to make the team," Zimmer said. "We don't know if any of these guys are going to make the team. We're always looking for guys, so we'll see what's going on."

'Right team around me'

Defensive end Everson Griffen, the longest-tenured Vikings player, begins his 10th NFL season in Minnesota in a curious position.

A restructured contract, which took about $3 million out of his pocket for this season, gives him the opportunity to become a free agent in 2020 should he reach benchmarks for playing time and performance this season.

Griffen said his focus is solely to "stay consistent" after missing five games last season due to mental health concerns and treatment.

"It's not about motivation; it's about being disciplined," Griffen said. "Last year was hard, but I got the right team around me now; my teammates, the coaches, the whole organization behind me and that feels good. I'm just going to stay disciplined and stay consistent."

Résumé building

When new Vikings running back De'Angelo Henderson was waived Tuesday by the Jets, he started applying for jobs outside of football. Henderson, a 2017 sixth-round pick by the Denver Broncos, has appeared in eight games in two NFL seasons, so he didn't think a team would come calling as quickly as the Vikings.

Henderson, who signed Wednesday, said he was "grateful" to turn down a job interview this weekend for a sales rep position.

"My body of work I've been able to do in the NFL, so far, hasn't been a lot," Henderson said. "I didn't think I was going to get another chance, so I started applying for jobs. I was on Indeed, building my résumé."