Novak Djokovic and Rafael Nadal go head-to-head in Wimbledon’s men’s semi-finals on Friday.

The other last-four match sees two of the tallest players in tennis do battle as 6ft 10in John Isner tackles 6ft 8in Kevin Anderson in a match sure to be dominated by serving.

Here, Press Association Sport looks at the key talking points.

What has Rafa got left in the tank?

After the exhausting semi-final against Juan Martin del Potro, which was just a minute shorter than his classic 2008 final against Roger Federer, Nadal probably could have done with a cold beer. Instead he headed home for a dinner of fish and salad, and a good night’s sleep. On Thursday he picked himself up and got back to the practice courts, returning to the routine that has carried him this far. He spent an hour there, ensuring everything continued to tick over ahead of his clash with long-time rival Djokovic. They have contested more matches than any other pairing in the Open era, and Djokovic holds a 26-25 lead. Nadal will need to be fresh on Friday to draw level.

Djokovic can show he is back to his best

Novak Djokovic knows Rafael Nadal's game inside out
Novak Djokovic (pictured) knows Rafael Nadal’s game inside out (Steven Paston/PA)

After seven consecutive wins over Nadal, Djokovic has lost their last two matches. Both were on clay, in Madrid last year and in Rome as recently as May. Grass is perhaps a leveller in the rivalry between these two, with Nadal favouring the clay and Djokovic the hard courts. Both are having strong fortnights and many experts suspect Djokovic is getting close to his very best again. This is the level of match where the theory will be put to the test, with world number one Nadal clearly in the mood for a third Wimbledon title and Djokovic hungry for a fourth. Some will think of it as effectively the final.

Is Isner simply unplayable this fortnight?

John McEnroe has tipped Isner to reach the final, having been impressed by his fellow American so far in the championships. Isner has sharpened up his all-round game, and with the improvements bolted to the remarkable serve he possesses, it is hardly a surprise he has improved on his modest previous best Wimbledon performance. It seemed a sure thing that one day he would go beyond the third round, but Isner has been surprised by his success this year. At the age of 33, he has slung down 161 aces in five matches and has yet to drop serve in 95 games.

Anderson needs to break the unbreakable

Finding a chink in Isner’s serve was beyond Milos Raonic in the quarter-finals, so it falls to Anderson to identify and then exploit a weakness. Trouble is, he is struggling to see one. Anderson’s verdict this week was that Isner has “arguably one of the best serves of all time”, and he pointed to the high percentage of first serves that his rival has been landing. He senses Isner’s confidence is rising by the round, giving him added belief in his ground strokes too. Anderson feels he can hold his own from the back of the court, and his own serve is a titanic weapon too, only not quite as fearsome as the Isner missile.