MADRID (AFP) – Argentina striker Lionel Messi, who has pleaded to be left out of Barcelona's opening league game to concentrate on his country's crucial World Cup clash with Brazil, could miss Sunday's Spanish Super Cup clash with Athletic Bilbao.

The Spanish champions said Thursday that Messi has a groin injury picked up in training for the midweek international friendly win in Russia, a match which he sat out.

Injured Messi eyes Brazil showdown AFP/Getty Images/File – Argentina striker Lionel Messi, pictured on August 8, 2009, who has pleaded to be left out of Barcelona's …

"I want to play all Barcelona's matches up to the game against Shakhtar Donetsk (European Super Cup on August 28), but then rest until the match against Brazil (Sept 5)."

Barcelona are due to open the defence of their La Liga title on Monday, August 31.

Argentina are currently in fourth place in South American qualifying for the 2010 World Cup finals with 22 points, just two ahead of Ecuador but five behind leaders Brazil.

Only the top four sides qualify automatically for the finals in South Africa.