An MRI taken at Stanford Medical on Thursday revealed 49ers cornerback Chris Culliver tore the ACL in his left knee while practicing as the gunner on a punt coverage drill earlier in the day.

As a result, Culliver will miss the entire 2013 season.

Culliver played 63.2 percent of the teams’ defensive snaps last year in which he was usually featured in nickel packages.

He also missed time in college at South Carolina in 2009 for shoulder surgery and in 2010 with a torn pectoral muscle, but bounced back to be taken by San Francisco in the third-round of the 2011 draft.

Following the news of the injury, Culliver’s friend, Ryan Sakamoto – CEO/Founder of Ninerfans.com – spoke to SFBay about No. 29’s outlook saying:

“Knowing Cully, his heart, determination, and work ethic, will allow him to have a fast recovery. This minor setback will not only work in his favor but motivate him to be an even stronger player in 2014.”

After final roster cuts next month the veteran will be placed on injured reserve, joining fullback Alex Debniak, wide receiver Brandon Carswell, and linebacker Darius Fleming, all of whom are out for the year.

Julia Reneé Rael was one of many fans offering positive thoughts to Culliver late Thursday, telling SFBay:

“It’s another setback, it’s a tough loss and he will be tough to replace, but I wish him a quick and speedy healing process.”

In the meantime, free agent corner and San Francisco native Eric Wright is likely to garner the 49ers attention as a replacement in the wake of Culliver’s injury.