Before each day’s play at the U.S. Open, Steve Tignor will preview and predict three must-see matches.

Angelique Kerber vs. Roberta Vinci

Head to head: Tied 2-2

Kerber sounded a little wary when she was asked about her quarterfinal opponent on Sunday, and she should be. The German and the Italian have split their four previous matches, and as we were reminded again last week, whatever Vinci’s form is like the rest of the year, you can throw it out the window when she gets to New York. Last year’s runner-up has taken advantage of a seed-free draw, and has lost just one set in her four matches. The 33-year-old’s ever-pesky game, based on slice backhands, changes of pace and 20th-century net skills, will be a challenge for Kerber. But the German, who hasn’t dropped a set in three Open rounds so far, has been up to most of them this season.

Winner: Kerber

Gael Monfils vs. Lucas Pouille

Head to head: Monfils leads 1-0

Once upon a time, this was the quarterfinal where Rafael Nadal was going to play Milos Raonic. Instead of that battle of generations, we’ll see an all-French one between the 30-year-old Monfils and the 22-year-old Pouille. Monfils can have trouble finding the motivation to beat his countrymen, but he pulled it off in his only meeting with Pouille, at the Australian Open in 2015. In that match, La Monf won 6-4 in the fifth set. Pouille, of course, has improved since then, as evidenced by his win over Nadal on Sunday. The question for him is whether three straight five-set matches will finally catch up with him. Monfils, by comparison, has won all of his in straights. And he has improved since last year, too. Monfils has been to the quarters twice before at Flushing Meadows, but never to the semis. Can he finally do it?

Winner: Monfils

Novak Djokovic vs. Jo-Wilfried Tsonga

Head to head: Djokovic leads 15-6

At times during the first week it was possible to forget that Djokovic was still playing in this tournament at all. His second-round opponent withdrew and his third-round opponent retired after six games. Seven full sets is all it has taken for the world No. 1 to reach the quarterfinals. Is that good news, because it has allowed him to rest his left wrist and right arm, both of which had been hurting him? Or will the extra time off throw off his body’s Grand Slam rhythm? We’ll find out when he faces the ninth-seeded Tsonga, who was sharp from the start in his last match, against Jack Sock. Jo is obviously going to have to be even sharper against the world No. 1. I’m thinking Djokovic will be refreshed by the break, and will record his 12th win in his last 13 matches against Tsonga.

Winner: Djokovic