Singapore: US Open champion Marin Cilic said Tuesday there was a strong chance of another new Grand Slam winner next year as men`s tennis opens up and the "Big Four" era winds down.
Cilic, speaking at the International Premier Tennis League in Singapore, said several players had shown they could challenge for a major, including Japan`s Kei Nishikori and Milos Raonic of Canada.
With Rafael Nadal returning from an appendix operation, Roger Federer now 33 and Andy Murray struggling for form, he expected an even more open season next year.
World number one Novak Djokovic from Serbia is the last of the "Big Four".
"I think now that things are pretty much open for the next season," Cilic told reporters.
"Rafa is a little bit injured, he`s going to be also back hopefully for the start of the new season, so that`s (recovery) going to make it even more competitive.
"I think next year we might see another new Grand Slam winner."
Cilic said Stanislas Wawrinka`s Australian Open win in January opened the door to a breakthrough year for several players, culminating in his (Cilic`s) US Open final against Nishikori in September.
"This year Nishikori played amazing, (Grigor) Dimitrov played also a really good season, Raonic was there all the time so it gives openings for those players to be there more often and being used to being at the end of the tournament," Cilic said.
France`s Gael Monfils was also hopeful about a Grand Slam breakthrough after completing his season with a victory over Federer in the Davis Cup final.
"The tour has changed a little bit and the top players also have changed a little bit," Monfils told journalists.
"Everyone improved a lot and as Marin said, guys like him and Wawrinka won a Grand Slam where before it was only the Big Four, as you guys call them.
"Definitely I hope next year I can be part of the new crop."
Cilic, 26, said he hoped that playing the IPTL, instead of his usual routine of focusing solely on fitness work at this time, would prove good preparation for the Australian Open.
"It`s a different way than I`ve been training in the last years but I think it`s something also good to try and see how I feel," he said.
"The format is not tiring, the matches are going very quick and still you are more in the competition mode... you can look at it a bad way or a positive way. I`m looking at it in a positive way."
The Croat is on the same IPTL team as his coach Goran Ivanisevic, enabling him to train while playing in the four-stop event which started in Manila last week and also visits New Delhi and Dubai.
But he admitted he would have to be careful of injuries after Ivanisevic, blaming the short warm-up in the high-paced tournament, injured a hamstring on Tuesday and had to be substituted.
"You have to adapt to the format, everything goes quick so you have to be a little more careful about your body," Cilic said.
"These things (injuries) are possible to happen but you have to be able to control it and adapt."
The IPTL has star players on four teams playing one-set matches with novel rules like no advantages, a 20-second serve clock and a timed, five-minute shoot-out at 5-5.