W2W4 at Wimbledon: Roger Federer and American contenders return to the grass

LONDON -- Back to your arena, Roger Federer. The eight-time Wimbledon champion returns to the grass Friday for the third round to face Jan-Lennard Struff.

The pair have met just twice before, with the world No. 2 claiming victory on both occasions. The German player has taken Federer to a tiebreaker on two occasions, but has only ever successfully snatched away one set.

And, unfortunately for Struff, the Swiss star has been on flying form so far this tournament -- he is yet to drop a set and has closed out both matches without seeming to break a sweat. He won 35 straight service points in his second round match against Lukas Lacko and at one point, each of Fed's service games was averaging little more than a minute.

Also with Marin Cilic taking an unexpected premature exit Thursday, Federer's run to the final is looking pretty straightforward ... shall we just call number nine now?

No. 25 Serena Williams vs. Kristina Mladenovic (Williams leads 1-0)

And speaking of Wimbledon greats, Serena will also be playing her third round match Friday against Mladenovic.

The 23-Grand-Slam-titleholder is looking in the best form we've seen her in since the birth of her daughter, and she's building her confidence in each round.

Mladenovic walked through her second-round match in straight sets and has been serving well through the tournament, but this match ought to be in Serena's hands. Though the 25-year-old is 11 years Williams' junior and will have mobility in her corner.

No. 11 Sam Querrey vs. Gael Monfils (Monfils leads 2-0)

After reaching the last four here in 2017, Querrey has risen through the grass-court rankings. The American will be looking to make his third consecutive fourth round appearance when he faces Monfils Friday.

Querrey overcame Serhiy Stakhovsky in the second round, where he lost just six of 60 first serve points and wasn't broken once.

Monfils, on the other hand, has had three sets taken to tiebreak already this tournament -- all of which have fallen in the Frenchman's favour, but he will no doubt be feeling the physical effects of the longer matches.

The pair have met twice before, both of which Monfils has won, but the popular Frenchman has never made the fourth round at Wimbledon.

No.10 Madison Keys vs. Evgeniya Rodina

It's been an up and down season for Keys, but she has performed well at the majors -- she reached last year's US Open final and this year's French Open semis, both of which she lost to compatriot and friend Sloane Stephens.

Two straightforward, straight-sets victories sets up her third round contest with World No. 120, Rodina.

Keys will be looking to make the fourth round of a grand slam for the 10th time in her most recent 12 attempts, while the same feat would be a career first for Rodina.

This will be the first time the pair have met.