In the NFL, now more than ever, a team has to have quality depth in the secondary. The Vikings, like any team, are trying to build toward that. But right now, they are not even close to being there.

Head coach Mike Zimmer knows it, and that's why he yanked old security blanket Chris Crocker out of semi-retirement for one more season on Monday. Per Mark Craig's assessment of the safety spot, which is is more urgently in need of help than cornerbacks but perhaps not by much:

Zimmer had eight safeties on the roster before adding Crocker. Other than Harrison Smith, the group has been a disappointment that merited Sunday's transaction.

Injuries to Jamarca Sanford, Andrew Sendejo and Robert Blanton have dogged the position since Zimmer was hired in January. Sanford, the incumbent, missed most of the offseason installment periods, while Sendejo sat out everything from the end of last season until coming off the physically unable to perform list and practicing in full pads Monday. Blanton was given the job to lose at the start of camp and then lost it four practices later when he pulled a hamstring.

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 his old, reliable friend.

Read between the lines — or even right on the page — and you could tell Zimmer was getting frustrated with the safety play. Here are a few of his quotes from various transcripts during camp:

July 25:

Q: What do you want to see from the safety position opposite of Harrison Smith?A: It is hard for me to evaluate that right now because I have not seen Andrew Sendejo and the walk-through today was the first time I saw Jamarca Sanford. But in the NFL, you have to have a guy that can cover pretty well because of the situations you can get into. Harrison is a pretty smart guy, so you can get by with a guy that is maybe not as intelligent and quickly making the snaps. But for our safeties, we are always looking for the same thing in the guys – guys who can cover, guys who are good tacklers, guys who can blitz well, and guys who are good at making decisions. For each position in the back end, we are looking for players that have great acceleration and can get out of a cut.July 28 (basically the same question as three days earlier):

Q: What do you see in the competition in the safety spot opposite Harrison Smith?A: Well right now, I would say (Robert) Blanton is a little bit ahead of the rest of the guys, but that will be a lot more determined when we get into the camp and preseason games, tackling, and how things go. He has been doing a lot good things as far as lining up, covering people, being in the right place, but with the safeties until you find out how they tackle, what kind of angles they take, what kind of instincts they have in the course of ball games, I really don't know.Monday:

Q: Does it make it easier when you have a couple of safeties that have experience at cornerback, like Robert Blanton and Antone Exum?

A: It helps a little bit. They're probably playing safety because they can't play corner.

And then in comes the 34-year-old Crocker. Perhaps he and Smith can be every down guys that stabilize the position and make depth less of an issue. Or maybe the questions about safety will dog the Vikings all season. Time will tell.