Walter Thurmond becomes the latest NFL player to retire early

Safety Walter Thurmond had a big 2015 season and could have cashed in with a huge payday in free agency. Instead, he's walking away.

According to multiple reports on Tuesday, including ESPN's Adam Schefter, Thurmond is retiring. He's 28 years old, with six seasons of NFL experience with the Seattle Seahawks, New York Giants and one last season with the Philadelphia Eagles.

It's easy to guess that concerns about concussions played a role. On Thurmond's Twitter account at the time of his retirement, three of his last four posts were about concussions — a comment on a story that BMX rider Dave Mirra had the degenerative brain disease chronic traumatic encephalopathy (CTE), a retweet of a story that former NFL legend Bubba Smith had CTE, and a GIF showing how the brain reacts when the human skull is hit.

Thurmond had reinvented himself as an NFL player last season. He moved from cornerback to safety, where he thrived with the Eagles. He reportedly had offers of more than $4 million a year, which is no surprise. He had a career-high 73 tackles and also three interceptions, after having just one interception his first five seasons. He also set career highs in sacks (two) and forced fumbles (two). He took to safety very well and could have had a lucrative and successful second half of his career at that position.

It's not fair to say early retirements are an epidemic for the NFL because among hundreds of NFL players only a handful have walked away due to health concerns, but it is a new and worrisome issue for the league. Last year there were a few retirements by players in their prime, most notably San Francisco 49ers linebacker Chris Borland after just one season. Borland said a big part of his decision was the concern over concussions.

It's hard for many of us to imagine walking away from the NFL when teams are preparing to offer more than $4 million a year to play. But Thurmond has other interests. The Eagles' site said he's an "avid film and art enthusiast." He tweets often about films. He has also tweeted about NFL player safety a lot this offseason.

Thurmond decided, for whatever reason, that the NFL life was no longer for him, no matter how much money he was leaving on the table.