The 36-year-old has not represented his country since January but is feeling so fit that he is already looking beyond the five-Test Ashes series starting in November.
''As long as the body holds together then to me you've got to be a better cricketer, and the body's feeling great, I'm training hard and everything is going well,'' McGrath told reporters during the Australian squad's four-day boot camp in Queensland.
''I know a lot of guys who have got a lot fitter and stronger when they are 40 than when they were 25,'' McGrath added.
''The older you get the more experienced you are so mentally you're a lot stronger. I'm pretty lucky that my action is fairly sound.
''As long as the desire and the hunger are still there I'll play as long as I can.'' McGrath, third on Test cricket's all-time list with 542 wickets, said his wife Jane was doing well in her battle to recover from cancer.
''At the moment it's probably the best we've been in the last seven or eight months,'' he said. ''Every day is getting better. As long as things go well at home and Jane's happy that's all that matters.
''I still love the game, still love playing, still love being around the guys and getting out in the middle and performing.'' McGrath, who has played 119 Tests and 221 One-day internationals since making his debut in 1993, was named in Australia's squad this week for a Tri-Series in Malaysia next month.
''A lot will depend on the tour of Malaysia,'' he said. ''It's a good test for me to see how things are going and also for the selectors.''