Bernard Tomic lost to Andy Murray in straight sets in the fourth round of the Australian Open—and gushed about the No. 2 seed afterward.

“When you play, he's got the balls coming back. He's so physical,” Tomic said. “He's on top of every ball. It's not like playing other guys 10, 15 in the world, my level. It's a different player and athlete. He's just fighting for every ball. He's on balance and he's prepared for every ball. He gets so many balls back. It becomes so frustrating. In positions where normally other players can't get it back, he gets it back. It forces you to go for more and forces you to overthink.

"You don't feel comfortable against these guys in these positions playing these players, even like [No. 1] Novak [Djokovic] and Andy. Their defense is just amazing.”

Murray will face David Ferrer in the quarterfinals. The 28-year-old two-time Grand Slam champion has finished runner-up in Melbourne four times. In 2010, he lost to Roger Federer in straight sets; in 2011 Murray beat Ferrer in the semifinals, then lost to Djokovic in three sets; he then lost four-set finals to the Serb in 2013 and 2015.

Murray is 12-6 against Ferrer. In 2015, Murray beat the 33-year-old at the French Open, the ATP Masters 1000 in Paris/Bercy, and at the ATP World Tour Finals.

Looking ahead to the match, Murray said that many top players like Ferrer are still in great shape even though they are aging. Federer is 34 years old and Ferrer, ranked No. 8, will turn 34 next month.

“Both of them have been around the game for a long, long time and been up at the top,” said Murray. “I can do that as well. You don't have to retire when you're 31 now or when you're 32. As long as you still have the passion and dedication to work hard, and obviously if you can stay injury-free, it's possible. Even Feliciano Lopez. He's 35 this year, too. There's a lot of guys that seem to be playing a little bit longer now. All it comes down to is really the body.

“[Ferrer] obviously works extremely hard. He's in good shape. He fights so hard in every single match. He's been rewarded for that with an unbelievably consistent career at the top of the game. This year he's made some changes to his racquet, which would suggest that he's still trying to improve and trying to learn and do different things.”