Agar was only brought to England originally as a \"development player\" for the first two Ashes Tests.
Nottingham: Australia coach Darren Lehmann forecast "outstanding" teenage sensation Ashton Agar would come into the game "more and more" after the left-arm spinner was handed a shock Test debut in the Ashes opener at Trent Bridge.
Agar, a 19-year-old Western Australia left-arm spinner, was only brought to England originally as a "development player" for the first two Ashes Tests.
But in a dramatic move involving Australia chairman of selectors John Inverarity, on tour selector and wicketkeeping great Rodney Marsh and Lehmann himself, Agar was preferred on Wednesday instead of off-spinner Nathan Lyon, a veteran of 22 Tests.
The stunning selection did not leak from the tourists' camp until fast bowling great Glenn McGrath was seen handing Agar his 'Baggy Green' cap, in a traditional presentation ceremony for Australia players making a Test debut, shortly before Wednesday's toss.
"The boys were good, they knew two days ago so we just had to see if they could keep it quiet and they did," Lehmann, appointed only just over a fortnight before this match after South African Mickey Arthur was sacked as Australia coach, said.
"For a 19-year-old kid, it's great," added Lehmann, a former Australia batsman.
"He's excited and you saw him when Glenn McGrath presented him with his cap, he had a tear in his eye and it's a big moment for him."
Just as England believe offspinner Graeme Swann can play a key role against Australia because his stock ball turns away from left-handed batsmen, of whom there are several in the tourists' line-up, so the fact England's top-order is mainly made up of right-handers helped boost Agar's case.
"We went for a left-arm spinner to take it away from all their right-handers," explained Lehmann after a day where Agar sent down seven wicketless overs, albeit for just 24 runs, in overcast conditions ideal for seam rather than spin bowling.
"He was nervous today (Wednesday) -- you'd expect that on the first day of an Ashes series.
"As the wicket wares, he'll come into the game more and more," Lehmann insisted.
Melbourne-born Agar came to prominence during the last Australian season by taking 31 first-class wickets at a shade under 30 apiece in his debut Sheffield Shield campaign for Western Australia.
Lehmann, then coach of Queensland, was impressed.
"I've seen him bowl a lot last year in Shield cricket and I think he's an outstanding prospect.
"He knows he has a lot of work to do and that's OK. We were happy to take the chance with him with all their right handers. He gets it in the right area and he can bowl."
For the 25-year-old Lyon, who ever since the squad was announced has had to cope with suggestions that Pakistan-born leg-spinner Fawad Ahmed, recently granted Australian citizenship, might jump ahead of him in the queue for an Ashes place, Agar's selection must surely have been a shattering blow.
However, Lehmann said: "He's been outstanding, the way he took it, and he's going to play a part in this Ashes series as well, there's no doubt about that."