If Juan Martin del Potro and Marin Cilic represent the shape of things to come tournament organisers might have to start raising the height of ceilings in locker rooms around the world.
The Argentinian and the Croatian, who will meet in the fourth round after comfortable victories at the Australian Open here today, are both 6ft 6in giants with the games to match their imposing frames.
Just as the careers of Andy Murray and Novak Djokovic, who were born within a week of one another, have followed similar paths, so there are common bonds between the two players considered most likely to emerge from the next wave of youngsters. Del Potro, a 6-7, 7-5, 6-3, 7-5 winner today over Gilles Muller, and Cilic, who beat David Ferrer 7-6, 6-3, 6-4, were born five days apart 20 years ago. Both are right-handed powerhouses who crack the ball with enormous strength from the baseline. Given their size you would hardly expect them to spin delicate webs in which to entice their opponents, but both can occasionally surprise with the subtlety of their touch.
Both won their first titles last year. Cilic got off the mark at New Haven in the build-up to the US Open, while Del Potro announced his arrival with a spectacular sequence of summer victories in four successive tournaments in Stuttgart, Kitzbuhel, Los Angeles and Washington. He followed that with a run to the quarter-finals in New York before going out in four sets to Murray in one of the matches of the tournament.
The two men have already lifted their first trophies of 2009, Del Potro having won in Auckland and Cilic in Chennai. Del Potro, who played in his first Tennis Masters Cup at the end of last year, is now up to No 6 in the world, while Cilic is at No 20.
Del Potro had enjoyed the more comfortable route to the third round here, beating Mischa Zverev and Florian Mayer without dropping a set. Cilic won in four sets against both Kevin Anderson and Janko Tipsarevic.
Muller, Del Potro's third-round opponent, had knocked out Feliciano Lopez, the No 27 seed, and Bernard Tomic, the Australian teenage sensation, in his first two matches. The 25-year-old from Luxembourg is a big server with a strong net game and came forward at every opportunity, though Del Potro would have won more quickly if he had made better use of his chances. Despite the power of Muller's serve – the world No 87 hit 22 aces – Del Potro had 24 break points but took just four of them.
The Argentinian was more than comfortable on his own serve, however, with Muller breaking only once. Del Potro hit 12 aces and put 73 per cent of his first serves into court. It was a match full of big winners, Del Potro hitting 62 and Muller 71.
Cilic won even more impressively against Ferrer, the world No 11, who reached the quarter-finals here 12 months ago and was a semi-finalist at the US Open in 2007. The Croatian appeared to have his work cut out when Ferrer made an immediate break of serve, but the Spaniard's game quickly fell apart after Cilic recovered to take the first set.
"It was a good performance from me," Cilic said afterwards. "At the beginning of the match he broke me in the second game. I think that woke me up a bit, which was good for me. I reacted very well and broke him back again and I was pretty well in the game from that moment.
"In the second and third sets I played much better. I was moving very well, not missing too many returns, which was really good for me. I was making him play a lot, giving myself a lot of chances."
The meeting here will be the first between Cilic and Del Potro as seniors. They met twice as juniors, Del Potro winning on each occasion. Does Cilic see the Argentinian as a long-term rival? "Yes, for sure, I think he has a good all-around game. He doesn't spend too much energy when he's playing. He has a huge serve, which helps him to win more easily and make him more comfortable with the points. I think he'll stick around in the future."
Del Potro was reluctant to see himself and Cilic as the two brightest prospects in the game. "He's playing very well and I am too, but we never know where either of us could be in three months," he said. "We just have to work and keep improving."
Did he see himself and Cilic as the most likely future challengers to the current top four? "No, I don't think so," Del Potro replied.
Pressed for his assessment of Cilic, Del Potro said: "He's very good. He has everything to be a good player – his service, his movement, his forehand. He will be in the top 10 or very close."