Over the last few seasons the San Francisco 49ers have made a habit of turning around the careers of highly-drafted defensive backs that didn't originally live up to their billings coming out of college.

Carlos Rogers and Donte Whitner are the most notable examples after not living up to expectations with Washington and Buffalo - where they were both drafted in the top 10 of their respective drafts. But they became stalwarts on the 49ers' highly-ranked defenses of the last three seasons while showing significant improvement from their tenures with their previous teams.

San Francisco has also made the most of corners taken late or not at all, like Tarell Brown (fifth round) and Tramaine Brock (undrafted).

Of those four, only Brock remains with the team after Whitner and Brown walked in free agency this spring. The 49ers released Rogers and are reaping the benefits of his departed $6.6 million cap figure as of June 1. That extra cap flexibility led to a lucrative extension for Colin Kaepernick

It's fitting, then, in an attempt to replace Rogers and Brown, the 49ers looked towards Chris Cook, a former second-round pick of the Minnesota Vikings who never quite played like a guy worthy of where he was selected. He struggled both on and off the field in Minnesota, dealing with run-ins with the law that bled into a lack of production on Sundays. Ultimately the Vikings elected not to bring him back after transitioning to new coach Mike Zimmer from Leslie Frazier this offseason.

"I feel like change was the biggest thing that I needed," Cook said after Tuesday's OTA session. "It changed my dedication coming to a team like this and seeing how much the coaches care about the players and how much the players care about each other. "It's really a brotherhood in this locker room and that's a big thing for me."

San Francisco signed Cook to a one-year deal for the veteran minimum this spring after the Vikings elected to let him walk in free agency after four disappointing seasons. In 2013, quarterbacks had a 140.3 rating when targeting him in coverage, including nine touchdown passes and a 71.2 completion percentage, according to Pro Football Focus.

Despite his unique combination of size (6'2", 210 pounds) and speed (reportedly 4.46 in the 40-yard dash), Cook never realized his potential the team saw when it selected him 34th overall in the 2010 draft out of Virginia.

"It's really a brotherhood in this locker room and that's a big thing for me." - Chris Cook

His standing with the Vikings was impacted heavily by his off-the-field troubles. In October of 2011, Cook was arrested on two charges after an alleged altercation with his girlfriend - one for domestic assault and another for intentional attempts to inflict bodily harm on another. He was also accused of brandishing a gun in a separate incident in which he was never found guilty.

In the spring of 2012, Cook was acquitted of those domestic assault charges after being suspended for 10 games to finish off the previous season.

Cook had shown signs of becoming a breakout player in 2011 before his team-issued suspension. And then his 2012 season was derailed by a broken arm allowing him to appear in just 10 games. He also missed four games in 2013 because of injury. In four seasons, Cook made just 34 appearances (29 starts), perhaps preventing him from fully developing as the Vikings would have hoped.

"I'm taking full advantage of my opportunity and I appreciate my opportunity I get to come out and play the game again," said Cook. "I had a rough year last year. I had a rough last four years. I'm just ready to come out and prove that I can do it, you know to help this team any way that I can - coming off the bench or special teams. Whatever it may be."

The 49ers hope Chris Cook can revitalize his career in San Francisco.

The 49ers are no strangers to off-the-field troubles. The situations surrounding Aldon Smith, Chris Culliver and Kaepernick have been well documented - although it's looking less and less like anything will come of the investigation surrounding Kaepernick in Miami.

And it's become clear: if a player can help the team between the lines, the front office and coaching staff are willing to take on that player's baggage. Part of that is due to the veteran leadership in the locker room, or the "brotherhood" Cook referred to.

If OTAs are any indication, it appears Cook has thrived in the early going with his new team. He's gotten the majority of his reps with the starting unit while Culliver works in slowly after sustaining an ACL tear last summer that cost him all of 2013. Culliver remains the favorite to start opposite Brock, but Cook will stay in the fold during training camp.

It's unusual for newcomers to jump returning players on the depth chart, but that's exactly what Cook has done by playing over Eric Wright in the early stages.

Wearing Rogers' old No. 22, Cook noted his affinity for his new position coach Ed Donatell, who has given Cook a lot of one-on-one time since joining the 49ers.

"Coach Ed really cares about his players. He takes every opportunity he can get to help us get better, whether it be one-on-one time, film study. He makes cut ups for us. He just dragged me out there after this to work on deep ball stuff just to tighten that part of my game up," Cook said.

With his physical traits, Cook embodies the new rage in the NFL made en vogue by the Seattle's big, athletic cornerbacks. And by drafting Dontae Johnson (also 6'2") in the fourth round in last month's draft, San Francisco is catching on.

Cook said he expects to be used in press coverage frequently, much like the Seahawks will continue to do with Richard Sherman and Byron Maxwell. But with limited contact allowed in OTAs, there's only so much they can do to work on pressing receivers.

"I've been watching my old press tapes," said Cook. "Me and T-Brock…the other corners and I will go out there and press each other and work on our steps. That's going to be a big part of our game too."

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