Even with the great advances made in sports medicine over the years, some injuries and conditions remain mysterious. As time goes on and baseball players begin and end their careers, new issues arise that the sport must unpack and attempt to remedy. In recent years, there has been one that pops up among pitchers that has the potential to derail careers: thoracic outlet syndrome.
To baseball fans, thoracic outlet syndrome can elicit a sense of extreme uncertainty. This comes from several examples of past players who have experienced the condition. To those in the New York area, the first case that might come to mind is former New York Mets star pitcher Matt Harvey. Harvey was diagnosed with thoracic outlet syndrome in 2016 after struggling during the season, coming off three ace-caliber seasons since his rookie year in 2012. Harvey was never the same pitcher, due to both the surgery he underwent for this condition and other injuries. Another prominent example in recent memory is the 2019 World Series Most Valuable Player, Stephen Strasburg. In 2019, Strasburg became the first pitcher in MLB history to record five postseason wins in a single season without a loss. Two years later, he began experiencing shoulder and neck issues and underwent surgery for neurogenic thoracic outlet syndrome. He never returned to his stellar form, appearing in only five games in 2021 and one in 2022 in what would be the last game of his career. He retired after the 2023 season having not appeared in a single game that year due to nerve-related issues with his thoracic outlet recovery.
Thoracic outlet syndrome occurs when blood vessels or nerves in the thoracic outlet region (the upper chest between the ribcage and clavicle) are compressed. This causes pain in the shoulder, arm or hand. The three types, arterial, neurogenic and venous, all have different implications.
Neurogenic thoracic outlet syndrome, the kind that struck Harvey and Strasburg, occurs when the nerves are compressed in the thoracic outlet area.
On Aug. 16, Philadelphia Phillies ace Zack Wheeler was placed on the Injured List due to a right upper extremity blood clot near his right shoulder. The following week, the team announced his diagnosis of venous thoracic outlet syndrome and that he would miss the rest of the 2025 season after getting decompression surgery. Venous thoracic outlet syndrome occurs if a vein is pinched, forming a blood clot in the thoracic outlet region.
If all goes as expected during his surgery, Wheeler could be able to return for the start of the 2026 season. However, this doesn’t guarantee that he will return as the same Wheeler that Phillies fans have come to recognize as a cornerstone of their rotation. Since joining the Phillies in 2020, Wheeler has put together a 69-37 record with an earned run average of 2.91 and 1,094 strikeouts. He’s been a mainstay in National League Cy Young races over the past few seasons. While Philadelphia has one of the deepest rotations in the game, Wheeler’s consistency will be sorely missed as the team pushes for a deep playoff run.
Thoracic outlet syndrome might be unfamiliar to those outside the baseball realm because it is fairly unusual. About one to three per 100,000 people are affected by the condition. The scariest part of thoracic outlet syndrome for Major League Baseball is how much remains unknown. While surgery usually allows players to return to games, it is not a surefire solution.
Watching some of the great pitchers of their eras go down with this mystifying condition is but a small concern for MLB. The sheer rarity of the condition makes it difficult to know how to move forward and ensure a higher rate of successful returns to the sport. It remains to be seen how Zach Wheeler will look upon returning from his surgery, but any fan of baseball should hope he returns to his dominant form, a pleasure to watch every five days.
