Frances Tiafoe, a finalist at last year's Cincinnati Open, was forced to retire from his Round of 16 match vs. Holger Rune during the second set on Wednesday because of injury. An official injury diagnosis hasn't been shared, but the Tennis TV broadcast said that Tiafoe's "back locked up" and he wasn't able to recover to finish out the match.

The American tennis star hasn't shown any signs of injury in tournaments leading up to the Cincinnati Open, so it's unclear how he injured himself.

Regardless of how the injury occurred, it couldn't have happened at a worse tine for Tiafoe. The U.S. Open begins on Sunday, Aug. 24, meaning Tiafoe's run there could be in jeopardy if the injury is serious. This only gives him about a week and a half to recover and make a decision about competing at the final major tournament of the year, one he's had a lot of previous success at.

Tiafoe is set to compete in the men's singles draw and the mixed doubles draw alongside fellow American Madison Keys. Some of the biggest names in tennis will be playing in the mixed doubles tournament, which starts on Tuesday, Aug. 19, meaning Tiafoe has an even quicker turnaround for that competition.

With his withdrawal, Tiafoe is expected to drop out of the top 15 in ATP rankings.

More on Sports Illustrated


This article was originally published on www.si.com as Frances Tiafoe Retires From Match at Cincinnati Open, Puts U.S. Open in Jeopardy.

Test hyperlink for boilerplate