McGrath, who underwent two ankle operations last year, is playing for Middlesex in the County championship on a short-term contract with his sights set on the Champions Trophy in England next month as well as Australia's Ashes defence in 2005.
"I haven't played a great deal in Australia recently so John Buchanan (Australia coach) said I needed a bit more cricket and there was a window between the end of the Test series against Sri Lanka and the start of the Champions Trophy," said McGrath.
The 34-year-old, one of 26 Australians playing in the County championship this season, insists that the surgery on his troublesome ankle has also handed him back his confidence to bowl full out once again.
"The ankle is great again. I had three spurs on the ankle. One of them was removed but if I had the other two taken off, I would have been out for too long.
"As it was, I snapped one off when I was preparing for the Zimbabwe series. Before the operation I couldn't put my front foot down as well as I liked but against Sri Lanka I hit the crease hard. I had been trying to get there for the last two years," added McGrath who has sent down 32,000 deliveries in his career which has yielded 440 Test wickets in 97 Tests.
The bowler has no doubt about the outcome of next summer's Ashes series.
"My prediction? 3-0," he said.