Wimbledon 2015: SW19 can give Andy Murray the edge over Novak Djokovic, says John McEnroe

Ivo Karlovic has lost all five of his previous meetings with Murray, including a second-round encounter here three years ago

Andy Murray faces the man with one of the biggest serves in tennis today but John McEnroe expects him to beat Ivo Karlovic – and then go on to win Wimbledon.

McEnroe believes Murray could be heading for a final showdown with Novak Djokovic and on the evidence of the first week sees the Scot as favourite to beat the world No 1 for the first time since the 2013 Wimbledon final.

“I think Andy’s healthier [than two years ago] and he does a lot of things better,” McEnroe said. “He’s generally being more aggressive. He’s trying to attack more off the return of serve.

“I think the one part you worry about a little bit is the second serve. It seems like his first-serve percentage has gone up though, which is key, so that he’s not vulnerable on that, which a guy like Djokovic can take advantage of.”

Murray, nevertheless, has to win three more matches before he will even think about the final. The first is against a player who broke into the world’s top 100 as long ago as 2003. Karlovic is the oldest man for 39 years to reach the fourth round at the All England Club, but at 36 the giant Croatian is playing some of the best tennis of his career.

Using his 6ft 11in and 16st frame to hit some monstrous serves, the world No 25 has struck 136 aces in his first three matches of the tournament, which is 57 more than Kevin Anderson, who is second on the aces leaderboard for those players left in the competition.

In Halle last month Karlovic hit 45 aces in beating Tomas Berdych, breaking the record for a three-set match on the men’s tour.

“It’s one of the four or five greatest serves I’ve ever seen,” McEnroe said. “He’s on a roll, he’s a big guy and he’s going to attack. And Murray’s just got to be on his A game returning. But he’s one of the great returners, so I think at the end of the day he’ll do it – but it’s going to be a few points here and there.”

Karlovic has lost all five of his previous meetings with Murray, including a second-round encounter here three years ago. The Croatian was foot-faulted 11 times in that match, after which he called his treatment “outrageous”, said the officials were biased and claimed the credibility of the tournament had been damaged.

Murray said: “It helps when you’ve beaten players before, but it doesn’t necessarily make the match any easier because he’s an extremely tricky guy to play against. He’s beaten some very good grass-court players here. Obviously in Halle his results were good. He beat Berdych there and he’s beaten [Jo-Wilfried] Tsonga here, so he’s very dangerous.”

McEnroe believes it would take “something extraordinary” to prevent a Murray-Djokovic final, “either like an unbelievable serving day or a guy like the great Roger Federer”. He added: “I think on this surface and with the crowd, which Murray seems to be utilising more and more – we even saw signs of that at the French Open – that will help him that maybe couple of per cent that could make a difference. Obviously it could go either way, but I like his chances better here than anywhere else.”

Murray, nevertheless, pointed to the strength of the players still in the tournament. “In the top half you’ve got Novak and Stan [Wawrinka] and [Marin] Cilic is still in there,” he said. “Kevin Anderson’s a very good grass-court player. Roger [Federer] is in the bottom half and around where I am there’s a bunch of guys that are 6ft [or more]. Karlovic is huge, but [Vasek] Pospisil and [Viktor] Troicki are both 6ft 4in. There’s a lot of big guys with big serves still around.”

Murray had treatment on a shoulder problem during his 6-2, 6-2, 1-6, 6-1 victory over Andreas Seppi on Saturday evening, but the Scot did a full practice session yesterday, after which he reported no physical problems.

McEnroe described the Seppi match as “more head games, mind games than anything else”. It was a remarkable encounter, Seppi winning five games in a row to take the third set after taking a medical time-out for treatment on his leg and Murray then winning the last six games after taking a time-out for treatment to his shoulder.

Neither player accused the other of faking injury to gain a tactical advantage but the Italian admitted he had joked with Murray at the end: “You used the same tactic as me when I called the physio.”

John McEnroe will join Tim Henman to play in the Champions Tennis at the Royal Albert Hall from 2-6 December. Tickets from championstennis.co.uk or call 020 7070 4404.