Courtesy John Urschel/Twitter

At age 26, Ravens lineman John Urschel’s day of playing football are over.

The brainiac left guard (and sometimes center) announced his retirement this morning, right before training camp practices were about to start. Urschel issued a statement via Twitter:

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— John Urschel (@JohnCUrschel) July 27, 2017

ESPN reports his decision is tied to a new study published this week in which researchers detected chronic traumatic encephalopathy (CTE) – a degenerative brain disease caused by repeated bashing of the head – in a whopping 99 percent of brains donated to scientific research by deceased NFLers.

He’s on a steadily growing list of players who are retiring early from football for fear of doing irreparable damage to their brains – and he might have the best case to make of all of them.

Urschel is currently studying for his doctorate in mathematics at the Massachusetts Institute of Technology, specializing in the fields of spectral graph theory, numerical linear algebra and machine learning. He’s aced his courses, published six peer-reviewed papers (with three more ready for review) and taken on the world’s best chess player, all while pursuing his pro football career for three seasons. These feats were enough to get him on Forbes’ 30 Under 30 list earlier this year.

Ravens head coach John Harbaugh issued a statement saying he respects Urschel’s decision. “We appreciate his efforts over the past three years and wish him all the best in his future endeavors,” he said.

Urschel has spoken before on his internal dilemma of whether he most enjoys hitting other linemen or studying advanced realms of mathematics. In a 2015 piece in the Players’ Tribune, he wrote: “I’ve fallen in love with the sport of football and the physical contact associated with it. Simply put, right now, not playing football isn’t an option for me.”

And in a January segment with HBO’s “Real Sports with Bryant Gumble,” he said, “It’s more important to me that I’m able to do the two things [math and football] I love. I don’t know if people have really done things that I’ve done before.”

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His absence will be noticed, of course, by a team already reeling from injuries. With Joe Flacco out to start training camp, and the team’s starting running back, cornerback and tight end all lost to injuries (and a suspension), the cards are not falling in the team’s favor approaching the 2017 season.

That’s no longer Urschel’s problem, though. He’ll be cheering them on from Cambridge this year.

This story has been updated with a statement from Urschel.

Ethan McLeod is a freelance reporter in Baltimore. He previously worked as an editor for the Baltimore Business Journal and Baltimore Fishbowl. His work has appeared in Bloomberg CityLab, Next City and...