Roger Federer and Serena Williams are back in the spotlight on Friday at Wimbledon.

Here, Press Association Sport looks at the main talking points on day five.

Struff of nightmares

Defending champion Roger Federer
Defending champion Roger Federer has yet to drop a set at Wimbledon this year (Jonathan Brady/PA)

Roger Federer has been making his customary serene progress so far and faces Jan-Lennard Struff in the third match on Centre Court. The eight-time champion is yet to drop a set this week, and in fact has won his last 27 sets at the championships. Struff did at least prove he is made of tough stuff when he came through a marathon set against Ivo Karlovic 13-11 in the fifth, but can he lay a glove on the Swiss superstar?

Serena getting stronger

Spare a thought for Kristina Mladenovic, who is next in the crosshairs of seven-time winner Serena Williams.  The American has made short work of her first two opponents and, although she will not admit it, the steady trickle of seeds going out has made the prospect of an eighth title a genuine one, less than 10 months after giving birth to her daughter. World number Mladenovic, a doubles specialist ranked 62 in singles, is unlikely to get in the way.

Venus in the mix

In fact the biggest hurdle to come for Serena could be sister Venus, who remains in contention to add to her personal tally of five titles, and they could meet in the semi-finals. The elder sibling is looking more fallible these days, dropping the first set in each of her opening two matches, but crucially she is finding ways to win. Kiki Bertens is next up, having lost to Venus in Miami earlier this year – despite taking the first set.

Murray Az new partner

Wimbledon 2017 – Day Thirteen – The All England Lawn Tennis and Croquet Club
Jamie Murray won the mixed doubles at Wimbledon last year with Martina Hingis (Adam Davy/PA)

Andy Murray may be absent but brother Jamie gets his campaign under way, starting in the men’s doubles with Brazilian partner Bruno Soares. They play Paolo Lorenzi and Albert Ramos Vinolas, before Murray embarks on a new partnership with former world number one Victoria Azarenka. Murray won the mixed doubles with Martina Hingis last year and will be looking to defend his title. No pressure then, Victoria. Wesley Koolhof and Elise Mertens are up first on Friday evening.