Australia have spun a major selection surprise by including the 19-year-old Ashton Agar, a Western Australian left-arm spinner, in their XI for the first Test against England at Trent Bridge.

Glenn McGrath's presence in the Australian team huddle a little less than an hour before the toss suggested a change to the team, and Agar emerged wearing his baggy green cap, presented on the strength of only ten first-class matches. His selection appears geared towards exploiting England's phalanx of right-handers, while also opening up a familiar wound for Kevin Pietersen.

However, it is a major blow to the career of the offspinner Nathan Lyon, who took nine wickets in his last Test match against India in Delhi. The selection also recalled events of the last Ashes series in Australia, when the previous selection panel dropped Nathan Hauritz on the eve of the series for Xavier Doherty, a move made with Pietersen in mind.

Unlike Doherty, Agar is a capable batsman and also a fine fielder. His inclusion leaves the tourists with a team that can be said to bat all the way down to No. 11.

"The main reason for the selection is taking the ball away from all their right-handers and we think this is a really important weapon in particular for this Test match on that particular wicket," the coach Darren Lehmann said. "In the tour match Michael [Clarke] felt he had good drift and straightened the ball nicely so that's just the way we have gone with the selectors in this Test match and we're looking forward to him playing really well."

Agar was not included in the initial Ashes squad, but after Lehmann's naming as coach he was upgraded to a place on tour, much like Steve Smith, the other notable inclusion in the team.

Smith's selection reflects a desire to have another right-hander and capable player of spin in the middle order, while also forcing David Warner to earn his spot back after poor form and a suspension for punching Joe Root during the Champions Trophy.

In one of the more convoluted paths to keeping a place in the team, Smith was initially left out of the Ashes squad but named vice-captain of the Australia A tour that served as a prelude. He was also on standby should an extra Ashes batsmen be required, an event that came to pass due to Warner's suspension and Michael Clarke's back trouble early in the tour.

Having battled gamely during his two India Tests, Smith went on to impress Rod Marsh and Lehmann - before he was appointed coach - on the Australia A tour, notably making a century against Ireland on a difficult first-day wicket in Belfast. He was then included for the final tour match against Worcestershire and played a pair of sprightly innings.

Smith is being groomed for leadership roles in the future by Cricket Australia, and was set to lead the A team to South Africa later this month before his Ashes tickets were upgraded. He will now have the opportunity to demonstrate how much he has developed since being a figure of some ridicule during the 2010-11 series, when his technique did not appear that of a top six batsman.

The rest of Australia's batting order was more or less as expected, Clarke moving to No. 4 having batted there in every innings so far on tour, Ed Cowan moving down to No. 3 and the pace attack comprising James Pattinson, Mitchell Starc and Peter Siddle.

Australia: 1 Shane Watson, 2 Chris Rogers, 3 Ed Cowan, 4 Michael Clarke (capt), 5 Phillip Hughes, 6 Steve Smith, 7 Brad Haddin (wk), 8 Mitchell Starc, 9 Peter Siddle, 10 James Pattinson, 11 Ashton Agar.