You don't have to ask Peter Siddle how he's feeling. His slump to his haunches with his face in his hands after he had bowled the last ball of the Adelaide Test should tell you. You don't have to ask Morne Morkel either. Ask the gym instead, because that's where he has been for the last few days.
Siddle has not had the recovery time Morkel and his colleagues have had, from mid-way on Monday, when South Africa began their match-saving fourth innings. The extra day and a half may be worth much more than a green-tinged gaze from the Australian camp, though. The South African attack has promised a show in Perth, driven by what they see as the advantage of being fresher.
"Talking to our physiotherapist, after the mammoth spell Siddle put in, it's going to be quite tough for him," Dale Steyn said. "Brandon Jackson said every time he runs a half-marathon and he runs another half-marathon a couple of days later, he can still feel the effects of the first one. If you can compare it, that's pretty similar to what Siddle put himself through."
Back-to-back Tests separated by a three-day gap have put Australia in a position where reshaping their entire attack is a possibility. That they have the reserves to do so is one thing, but that they may need to is another.
South Africa do not have that luxury so they won't spend too long thinking about it. They only brought four seamers to Australia and could end up using all of them in a Test for the second time on this tour. To do that, they need a pack that is fit more often than not: bowlers with the resilience of Shaun Pollock, who would tirelessly clock in overs, and the energy of Makhaya Ntini, whose reserves were so endless that he ran back to his mark every time.
Vernon Philander's lower-back problems that kept him out of the second Test meant they will not have a 100% record. Rory Kleinveldt is joked about as more meaty than muscular but South Africa have reason to believe they have the edge in fitness. In Steyn and Morkel, they have what trainer Rob Walter calls the "ideal players" to work with, and the attention given to the rest is focused on getting them to that level as well.
"In Dale you have a very sound action and a very strong athlete," Walter told ESPNcricinfo. "And Morne is someone who looks after himself very well. In an ideal world, everyone would be a Steyn or a Morkel. But everyone wants to improve, including them, and that's all I can ask for."
Philander, for example, was back in training as soon as his back released. He spent time in the nets on each of the final three days in Adelaide to get his bowling loads up ahead of the third Test. "People think that Vernon didn't do anything while he was injured but he is not the kind of guy who takes five days off," Walter said. "He has been doing enough to make sure he is ready."
That may not necessarily be a positive. Before the second Test, Philander was the bowler who had put in the most time at the nets and Gary Kirsten even joked that may have been the reason for his injury. Managing bowling loads is proving to be one of the toughest balancing acts in cricket. Sports scientists are developing limits to cater to individual needs as they try to get it right. In Australia, anything above 55 overs in a Test starts to raise management's eyebrows, but Walter said he doesn't have those targets at the moment for South Africa.
"I'm not hugely focused on that, especially because if a bowler is over 23 years-old, their threshold can increase anyway. It's the younger guys you need to watch," he said. "What's important for us is to monitor the recovery process, which starts with rest and then using all the methods available to us like ice baths, massage and compression."
One of Walter's most publicised methods was taking the bowlers for a recovery swim in the Indian Ocean in Durban during a Test. While some were aghast that players were leaving the ground while a match was going on, Walter said there was nothing unusual about travelling a short distance because it provided maximum benefit. "The temperature of the sea, the salt content, and the buoyancy of the water means it is something we always try to use. We've definitely reached a stage where guys are required to be better conditioned. And we have to do what we can to get there."
For Steyn, there is no special reason for his problem-free run. "I'm pretty blessed in that I've got a good action. I haven't struggled with too many injuries apart from the bad foot hold." Other bowlers may wish their issues were only as deep as that.

Firdose Moonda is ESPNcricinfo's South Africa correspondent