No. 1 Jannik Sinner faces No. 16 Grigor Dimitrov today in a thrilling grass-court matchup — here's how to tune in.

In a video of the moment, it looked as though the 34-year-old Dimitrov injured a pectoral muscle on a volley. Almost immediately after the hit, he fell to the ground, clutching the right side of his chest in pain.

Grigor Dimitrov broke silence following a heartbreaking retirement from his Wimbledon fourth-round clash against world no. 1, Jannik Sinner. Grigor forged a 6-3, 7-5, 2-2 advantage before shoulder pain forced him to stop, marking one of the most devastating moments of his career.