Nicolai Boilesen's prospective place in Denmark's UEFA EURO 2012 squad is in doubt after he suffered a relapse while stepping up his recovery from the hamstring injury which has blighted his season.
AFC Ajax confirmed on their website that their left-back, capped twice by his country, will not play again this term following the setback in training on Monday.
It is the third time the 20-year-old has injured his right hamstring since 18 September, when he tore the muscle in an Eredivisie fixture against PSV Eindhoven.
The former Brøndby IF player made his return after five months out in the UEFA Europa League round of 16 first-leg defeat by Manchester United FC but has not featured since after complaining of discomfort during that 28-minute cameo.
Denmark will play Group B rivals Germany, the Netherlands and Portugal at the forthcoming UEFA European Championship in Poland and Ukraine.
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