In an article for The Players' Tribune, Monroe formally announced his retirement Thursday and cited concerns over concussions and his long-term health as the primary reasons behind his decision to call it a career.
Monroe also stated he was confident that he could still play football at a high level and wrote he would miss the game-day energy that kept him going throughout his career.
"I'm going to miss the excitement of being part of something that so many people love so much," Monroe wrote. "An emotional roller coaster gets underway at the beginning of every NFL season. Passions and emotions run as high in the league as they do in any other profession. On any team in the NFL, you can feel the intensity of the game simply by walking into the practice facility every morning."
ESPN first reported Monroe's decision.
The 29-year-old Virginia grad and former No. 9 overall pick by the Jacksonville Jaguars played in 93 games over his seven-year career. He was dealt to Baltimore back in 2013 for a fourth and fifth-round pick and signed a five-year deal after his first season in purple.
Monroe's falling out with Baltimore was just as swift, though. Coach John Harbaugh did not mince words when asked about the team's ongoing efforts to trade him this offseason. Baltimore held Monroe out of a minicamp practice amid negotiations and pivoted directly to No. 6 overall pick Ronnie Stanley as their left tackle of the future once they released Monroe.