Andrei Shevchenko knows that when he walks onto the pitch to face England in Donetsk on Tuesday evening, he could be wearing the colours of the Ukrainian national team for the final time.The 35-year-old's brace in the 2-1 victory over Sweden had sparked hope of a glorious finale to his international career but after Friday's 2-0 loss to France in Euro 2012 Group D, Ukraine no longer have any margin for error.The calculations for the co-hosts are simple: to reach the quarter-finals, they must beat an England team buoyed by a thrilling 3-2 win over the Swedes and bolstered by the return from suspension of the swaggering Wayne Rooney.With so much at stake, Ukraine will hope that its favourite sporting son can roll back the years once again and delivery a victory that will take the country into the last eight of a major tournament for only the second time.Shevchenko will bow out from international football once the Euro is over, but another two goals at the tournament would allow him to sign off with 50 goals in the yellow and blue of his country.He already played a key role in Ukraine's last quarter-final incursion, as the attacking spearhead of the team that reached the last eight at the 2006 World Cup before falling to eventual champions Italy.Six years ago, however, Shevchenko was in his pomp.After seven prolific years at AC Milan, his name had become a byword for lethal finishing and his legacy was still to be tarnished by the disappointing three-year spell at Chelsea that began after the tournament.Now, he is in the twilight of his career, and yet his match-winning headed double against Sweden proved that the goalscoring instincts that saw him claim 175 goals in 322 games for Milan remain intact.The sight of Shevchenko wheeling away from the Swedish goal after scoring the equaliser in Kiev last Monday, an expression of unbelieving ecstasy etched across his face, is already one of the tournament's defining images.The catharsis was palpable.The knee and back injuries that dogged him last season tempered expectations about his capacity to make an impact at Euro 2012 and Shevchenko admitted last year that he was concerned he might "embarrass" himself.Instead, he has rediscovered his role as the national hero and Sergei Rebrov, his strike partner in the Dynamo Kiev side that reached the Champions League semi-finals in 1999, says it should never have been in doubt."Unfortunately, in Ukraine people think that if you are over 30 you should stop playing," he told the UEFA website."They have been saying it about Andrei for the past few years but every time he has proven otherwise. This season, and in other seasons, he has shown that it's still too early to write him off."I know he has been working hard to be ready for the Euro and the first game showed that it was not in vain. He is a real leader and a captain."Shevchenko's Dynamo contract is due to expire next month and although the club where he first made his name have suggested he could be offered a new deal, the player himself has hinted he could be tempted to move abroad.His brace against Sweden proves he still has much to offer but before he can begin to think about an exotic final pay-day, he will want to finish the job properly with Ukraine.The encounter with France left him with water on the knee, casting his participation against England into doubt, but it seems unlikely to prevent him from making what could be his final curtain call.