The Detroit Lions haven't had much luck when it comes to keeping their defensive backs healthy. Last season especially, the Lions seemingly had a different defensive back go down each week with some kind of injury.

It turns out that they had 13 different secondary lineups in 2012, according to new defensive backs coach Marcus Robertson. That's not a good number, especially compared to the San Francisco 49ers, a team that was on the complete opposite end of that spectrum. From MLive:

"One of the things I admired the last two seasons is I've been following the San Francisco 49ers," Robertson said. "They played with five defensive backs for 32 games, plus the playoffs, the last two years. I went up and spoke to Ed Donatell and asked him, 'How did you do that?' He gave me some insight on how he did it, and I'm taking heed to that and trying to implement that into what we're doing to try to get our guys as healthy as possible."

So what did 49ers defensive backs coach Ed Donatell share with Robertson? Robertson didn't get into too much detail, but he did stress the importance of players being honest about their injuries. Robertson brought up cornerback Chris Greenwood as an example of how not being honest can backfire.

"One thing you deal with when you deal with players, and I'll take Greenwood, for example," Robertson said. "Greenwood had the sports hernia. Well, he had it for some time and didn't want to tell anybody because he wanted to make the team. What's most important, in my opinion, is your health. Ultimately, what ended up happening is you didn't let anybody know, and I'm looking at you saying, 'You're not the same dude that I saw two weeks ago. What's wrong with you?'

In other words, if something is wrong, Robertson wants to know about it so the problem can be taken care of as soon as possible. Perhaps that's part of the reason why the Lions decided to go ahead and have rookie cornerback Darius Slay have surgery to repair his torn meniscus. Robertson said the injury isn't a "major concern" of his at this point in time, and the Lions surely didn't want it to be a concern come training camp or the regular season. By getting the problem corrected now, Slay should be good to go by the time training camp begins, allowing him to hit the field and contribute early in his career.