What to Watch Monday at Wimbledon

Kvitova, the two-time Wimbledon champion, was a finalist at the Australian Open, losing to Naomi Osaka. She has looked particularly confident in the last week on the grass, making her first run to the round of 16 in five years without dropping a set. Konta, the top British woman, has also looked extremely composed, but showed some signs of weakness in her third round matchup against Sloane Stephens. Kvitova’s big serve and excellent timing on groundstrokes can make it difficult for Konta to break ahead on the fast service.

Humbert, a 21-year-old Frenchman playing in his first Wimbledon, has had a remarkable run, outlasting 16th-seeded Gaël Monfils in the first round and consistently outplaying 19th-seeded Felix Auger-Aliassime in the third round. His next test will be much harder, as he faces Djokovic, the world No. 1 and defending Wimbledon champion (third match on No. 1 Court, ESPN2). Although Humbert’s aggressive style is well suited to the grass, Djokovic has made a career of being able to physically outlast players who feel as if they have to hit the lines in order to have a chance at winning a point.

In the last year, Nishikori has been the epitome of consistent performance, reaching at least the quarterfinal of each Grand Slam tournament. Kukushkin is having one of the best tournaments of his career, reaching the round of 16 at a major for the first time since the 2012 Australian Open. In the second round, Kukushkin beat John Isner, the No. 9 seed who reached the semifinals at Wimbledon last year. Kukushkin managed to break the hard-serving American four times during the match, even though Isner hit 34 aces. While Nishikori has played well so far, he hasn’t played anyone who has been able to push him on his way to the second week. Perhaps Kukushkin can give him his first real test.

For the first time since 2007, two American men will meet in the second week of a Grand Slam event. Querrey, who has been recovering from an abdominal injury, lost in the final of the Eastbourne International in the run-up to Wimbledon and is playing close to the level that saw him reach the semifinals at the All England Club in 2017. He beat Dominic Thiem, the No. 5 seed, in the first round in four sets, and has yet to drop serve this tournament. Sandgren has also been playing impressively, beating 20th-seeded Gilles Simon and No. 12 Fabio Fognini. Sandgren won his first career title earlier this year at the Auckland Open, and if he is able to unlock the secret to breaking down Querrey’s powerful serve, he may continue to outperform expectations.