Before each day of play at Roland Garros, we'll preview and predict three must-see matches.

Tiafoe is 17, has an 0-1 ATP record, has never played a match in a main draw at a Grand Slam, and as of this weekend was ranked No. 287. Yet the eyes of U.S. tennis will be on him as opens play on Court 5 on Monday. He’s the most highly touted American junior in recent years, and the only one to sign up with Jay-Z’s agency—he could, in other words, be very good for U.S. tennis. But is he good enough to beat the 36th-ranked Klizan, who knocked off Kei Nishikori in Paris last spring, and Rafael Nadal in Beijing later in the year? Probably not. Winner: Klizan

Stephens already has a fairly extensive history, on court and off, with the younger of the Williams sisters, but she has never faced the elder. Sloane says that clay is her favorite surface, and she has backed up those words at the French Open, where she has reached the fourth round each of the last three years. She’s also coming off a semifinal result at Strasbourg last week. Venus was a finalist at Roland Garros back in 2002 (when Sloane was all of nine years old), but in her last three trips, she’s won a total of two matches. This one could be close, but the 15th-ranked Venus should have the edge, mentally if not physically, over the 41st-ranked Sloane. Winner: V. Williams

While it doesn’t involve a top seed, this match could have a bearing on the outcome of the women’s event. Stosur may be the game’s unlikeliest dirtballer; the Aussie reached the final at Roland Garros in 2010 and comes in this year after winning the tune-up event in Strasbourg. If she reaches the third round in Paris, she could face Maria Sharapova. Last year Stosur led Sharapova by a set here before collapsing 6-0 in the third; the winner of another meeting between them would be in a strong position to go very deep in the tournament. But Brengle, a 25-year-old American, could play the spoiler. She nearly beat Stosur in their only meeting, and had a nice run on clay in Stuttgart last month. Winner: Stosur

For more 2015 French Open coverage, go to our tournament page:

!