Madison Brengle’s retirement came with a twist on Monday. The Delaware native fell to 16-year-old Kayla Day on Day 1, after retiring when down 6-4, 4-2 in the second set. As it turns out it wasn’t the typical tennis injury that caused Brengle to pull the plug. It was a drug test, administered by the World Anti-Doping Agency on Saturday.

More: Cilic on New Coach and U.S. Open Aims

Brengle told reporters after the match that she has suffered from a vein condition her whole life and that the drug test on Saturday caused her right forearm to swell and ache.

“Every time I get one of these tests the same thing happens, and I tried my best to get ready for tonight,” a teary-eyed Brengle said, according to Michael J. Lewis of the News Journal. “But in the second set I started to lose all feeling in my hand and my arm, and if you can’t feel the racket, it’s really hard to play. It’s the U.S. Open and I tried to fight through the pain as much as I could.”

Brengle, ranked 50, reached the third round at the U.S. Open last year.

“The only way it gets better is with rest and time,” Brengle said. “I’ve had work with the physios and I’ve sleeping with the compression sleeve (since Saturday) but it just takes time to heal.”

Brengle gave full credit to Day for the victory, but couldn’t hide her disappointment about her cruel fate. “[She is] a great player and I hope she has a great tournament, but it’s just really disappointing when you can’t even hold your racket without pain,” Brengle said.