Antony Davis

Former Rutgers offensive lineman Anthony Davis, 25, retired from the San Francisco 49ers on Friday. (Cary Edmondson-US PRESSWIRE)

In news that would qualify as a shocker if it wasn't happening so frequently this offseason, San Francisco 49ers tackle Anthony Davis announced his retirement — at least temporarily — from the NFL on Friday. The 25-year-old former Rutgers star has played five seasons in the NFL.

The 11th overall pick in the 2011 draft, Davis is the highest pick in Rutgers history. After playing in every game in his first four NFL seasons, Davis missed nine games last season due to injury.

Davis suffered a concussion against the Giants in Week 11 that sidelined him for four games. Like many players who have retired at a young age this offseason, the head injury was a factor in Davis' decision.

"After a few years of thought, I've decided it will be best for me to take a year or so away from the NFL. This will be a time for me to allow my Brain and Body a chance to heal. I know many won't understand my decision, that's ok," Davis said in a statement. "I hope you too have the courage to live your life how you planned it when day dreaming to yourself growing up. Your Life is Your dream and you have the power to control that dream. Im simply doing what's best for my body as well as my mental health at this time in my life."

Davis indicated on Twitter that his retirement won't be permanent.

Davis signed a five-year contract extension in 2013 worth more than $37 with $17 million guaranteed. The contract runs through the 2019 season.

Davis, a four-star recruit from Piscataway, left Rutgers after his junior season. The 6-foot-5, 323-pounder starred under former coach Greg Schiano, although they had a rocky relationship.

Davis has been a firm supporter of current Rutgers coach Kyle Flood, who coached the offensive line during Davis' college career. Davis was at Rutgers' spring game in April, spreading a message to New Jersey recruits to stay home for college.

Dan Duggan may be reached at dduggan@njadvancemedia.com. Follow him on Twitter @DDuggan21. Find NJ.com Rutgers Football on Facebook.