Yankees’ Phil Hughes was placed on the Disabled List on April 15 with a “dead arm”. But according to Bryan Hoch of MLB.com, Hughes may be suffering from Thoracic Outlet Syndrome, a nerve and circulatory condition.

Hughes is scheduled to see Dr. Robert William Thompson in St. Louis to determine if he indeed does have TOS and what the necessary course of treatment would be adds Hoch.

“We can’t tell you if he has it or if he doesn’t have it, but we’re sending him to a specialist,” manager Joe Girardi said.

The TOS is a group of disorders that occur when the blood vessels or nerves in the thoracic outlet — the space between your collarbone and your first rib — become compressed. This can cause pain in your shoulders and neck and numbness in your fingers.

Common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive injuries from job- or sports-related activities, certain anatomical defects, such as having an extra rib, and pregnancy. Even a long-ago injury can lead to thoracic outlet syndrome in the present (via Mayo Clinic’s website).

Hughes struggled in his first three outings this season. He is 0-1 with a 13.94 ERA and 3 SO in 10.1 innings, and his opponents are hitting .396 against him.