Safety Jamarca Sanford has started 41 games over the last three seasons for the Vikings, but he's in a four-way competition for his starting strong safety spot having to prove his ability.

It's just another training camp for the seventh round pick in 2009.

"A lot of people told me I wouldn't last a year in this league," Sanford said. "Now I'm going into Year 6. It's nothing different, just another hump in the road I've got to get over."

Sanford will get his first live action on Saturday against the Cardinals after missing the preseason opener against the Raiders with back spasms. He's had to play catch up throughout the offseason as Sanford also did not participate in OTAs and minicamp.

"It was a setback but that's part of the game," Sanford said. "Injuries, it's a physical game. You always have tweaks. It didn't help the situation at all, kind of took a step back not being out there and getting the mental reps."

With injuries to Sanford, Andrew Sendejo and Robert Blanton, the Vikings signed Chris Crocker to compete at strong safety. Crocker has received the majority of the first team reps this week given his familiarity with head coach Mike Zimmer's defense.

There's a good chance the newly-acquired safety will start against Arizona. Sanford will get his shot during the game however as Zimmer said he plans to divide the playing time among the four safeties.

The new addition will make his battle to retain that starting spot even more challenging, though Sanford won't treat Saturday's game differently.

Sanford has been in similar situations throughout his career, battling to secure a starting spot with the Vikings.

"I've been fighting all my life," Sanford said. "I'm not the prototype safety – 6-2, 220 (pounds). I'm 5-10 — stretching at 5-10 — 200-to-205 pounds. Size goes against me but it's not about the size. It's not the size of the dog, it's the fight in the dog. I know I put a lot of effort this offseason to work my rear end off to come back and help this team."