If the complicated term sounds familiar, it's because former Tigers pitchers Jeremy Bonderman and Kenny Rogers dealt with the same condition, as have many other pitchers in recent years. Some required surgery to remove the restriction, depending on the severity. The hope is that the 25-year-old VerHagen will not.
"It's possible," head athletic trainer Kevin Rand said of surgery, "but at this time it's not being considered."
VerHagen complained about soreness in the clavicle while pitching, Rand said, but it didn't bother VerHagen until after he threw. Meanwhile, Rand said, VerHagen was still pitching relatively well and without restriction.
By the time VerHagen made his lone appearance for the Mud Hens on May 25, he was dealing with numbness in his fingers, too. That forced both player and team to do some searching to figure it out.
That led VerHagen to Dr. Greg Pearl, the Texas-based specialist who worked with Bonderman, Rogers and others.
The diagnosis was TOS, but somewhat different than what Rogers and Bonderman faced. They had to undergo surgery to remove the restriction, including angioplasty for Bonderman and the removal of a rib for Rogers.
In VerHagen's case, Rand said, it's more a matter of a nerve being pinched, not a blood vessel.
"It's a neurological thoracic outlet, not arterial," Rand said. "So we are hoping we can get through it with [physical therapy]."
The idea is that therapy could open up the restriction and get blood flowing normally again. But until and unless that happens, there's no timetable on when VerHagen might be able to pitch again.
Thus, VerHagen, who impressed down the stretch last year and made this year's Opening Day bullpen before struggling, now has his career on hold. Meanwhile, the Tigers' relief depth takes a punch without VerHagen, a converted starter who could pitch anywhere from long relief to setup while throwing 96 mph.