Source: Vikings DT Sharrif Floyd dealing with nerve issue in knee

Minnesota Vikings defensive tackle Sharrif Floyd is dealing with a nerve issue in his right knee after having surgery to clean up his meniscus last September, according to a league source.

The nerve issue is preventing Floyd's quadriceps from working properly and could be career-threatening, according to the source.

USA Today first reported the details of the injury.

Floyd posted a message on Instagram last week that suggested he might be headed toward a career crossroads.

My 🙏🏽 to the big guy #upabove we've been on this train 🚂 for so long, you have blessed me in more why's then I could've possibly imagine. For that I I'm truly thankful. You've been there when there was no one around, you've held me together when I thought I was at my edge, you've aloud me to play a game that kids dream about to this day. For that I continue to place my hands together 🙏🏽 I come to you tonight that same kid in 2006, not moved by greed, not moved by negativity, not moved in bad behavior. I'm down on one knee praying my road doesn't end here.... there are so many more lives to touch, so much more joy to spread. You've believed in me for to long to turn your back on me now. Don't let me go out this way. All I ask is for a fighting chance... this game means so much to me and the foundation is still being laid one stone 💎 at a time. I'm hurting and I don't know how to say it aloud, I am truly humbled in your grace. Grant me one last run, I promise I'll lay my soul on the line. #humbleandhungry #215raisedme #begreat73 #savagelife #unlockthecage #notdoneyet #cametofartogiveup #watchmework #pleasedoubtme #level40training

A post shared by sharrif floyd (@humble_hungry_73) on Mar 23, 2017 at 9:51pm PDT

The Vikings have said he is continuing to rehab. Floyd saw specialists for much of last season after playing only in the team's first game.

His $6.757 million fifth-year option, which was previously guaranteed only for injury, became fully guaranteed March 9.

Floyd, a former first-round pick, dealt with knee injuries in 2014 and 2015, and he missed much of the Vikings' 2016 offseason program because of ongoing issues after having a piece of cartilage removed from his left knee during the 2015 season.

After playing in the Vikings' season opener at Tennessee, Floyd was ruled out for the home opener against Green Bay on Sept. 18, and he underwent surgery on his right knee on Sept. 22.

His injuries drew the ire of coach Mike Zimmer, who'd said he was "kind of used to" Floyd being hurt.

Floyd was shelved long beyond what the Vikings initially expected. They kept him on their active roster until Dec. 12, effectively playing with a 52-man team. When Zimmer was asked in November why the Vikings hadn't yet put Floyd on injured reserve, the coach said, "We didn't think it was going to be six years' worth of hurt."

When the Vikings placed Floyd on injured reserve, Zimmer said that the tackle hadn't had a second operation after his initial surgery in September. USA Today reported on Thursday, however, that Floyd had a subsequent operation after his initial surgery.