By Ricky Dimon Even before Friday, emotions were boiling over in the Billie Jean King National Tennis Center bubble. Kristina Mladenovic said that players are being treated like "prisoners." Kirsten Flipkens complained that she isn't allowed to leave New York and go home despite being eliminated from the tournament. Dominic Thiem was upset that he could not drink out of a … [Read more...] about Tennis Bubble Burst ? • U.S. Open Controversy Reaches New Heights With Zverev vs Mannarino Match That Almost Wasn’t