MANKATO, Minn. -- Former Cincinnati Bengals safety Chris Crocker is 34 years old with no desire to play anywhere other than Minnesota. The offseason passed, training camp opened and yet the Vikings still had not reached out to him with a contract.

But Crocker, the 11-year veteran with five different teams, knew old friend Mike Zimmer would pull that familiar personnel trigger eventually. So Crocker was ready. In fact, he was working out Sunday morning when Zimmer, fed up with the injuries and inconsistencies at the safety position next to Harrison Smith, finally called to essentially drag Crocker out of retirement for the third consecutive season.

"I never retired," Crocker said. "You're always kind of ready, especially when you have a guy like Zim that you can play for. He said I could come in and help these guys get better and also come in as a playmaker."

Crocker was on the field in full pads on Monday. If he gets his camp legs under him in time, he could play as early as Friday's preseason opener against the Raiders at TCF Bank Stadium.

"At this point in my career, I really didn't want to go anywhere else," said Crocker, who played the past seven seasons with Zimmer as his defensive coordinator in Atlanta and Cincinnati. "I'm not starting over. I wanted to come here and play for a guy who has meant a lot to my career. I've given him everything I have. Just empty the gas tank and see where it goes."

Crocker arrived in Minnesota to a system he's been in since 2007 because Zimmer knew the seven safeties other than Smith weren't cutting it as far as being a front-line player. So Crocker was given a one-year deal worth the veteran's minimum salary of $955,000. Undrafted rookie defensive end Rakim Cox was released to make room for him on the roster.

Injuries to Jamarca Sanford, Andrew Sendejo and Robert Blanton have made it impossible for anyone to gain traction next to Smith. And that was alarming for Zimmer considering last year's Vikings pass defense ranked in the bottom three of nearly every statistical category, including 31st in yards allowed.

Sanford, the incumbent, missed most of the offseason installment periods, while Sendejo missed everything from the end of last season until coming off the physically-unable-to-perform list and practicing in full pads on Monday. Blanton was given the job to lose at the start of camp and pulled his hamstring four practices later. He's still sidelined.

Kurt Coleman, Mistral Raymond and rookie Antone Exum have seen time with the first unit in camp, but weren't good enough to keep Zimmer from reaching out to Crocker one more time. Of those three, Coleman has the best chance to stay competitive in practice, while Exum is a guy the team might want to stash on the practice squad.

"I think I've been accountable, that's the biggest thing," Crocker said. "And he's just so honest. You really appreciate a guy who is going to tell you whether you're good or whether you're bad. At the end of the day, you know where you stand. I've always played at the highest level playing for a guy like that."

Crocker has 554 tackles, 14 1/2 sacks, 60 passes defensed and 15 interceptions in 151 games with five teams. Injuries in the Bengals' secondary brought him back for for 13 games and nine starts in 2012 and for 12 games and three starts last season. Both years, he helped the Bengals' defense lead Cincinnati to the playoffs.

That seems like a long-shot at best in Minnesota. But, for now, Zimmer feels a lot better now that he's security blanket has followed him from Cincinnati.