Argentina coach Diego Mardona, right, comforts defender Walter Samuel as he leaves the pitch injured during their win over South Korea on Thursday. ((Daniel Garcia/AFP/Getty Images))

The possible absence of Walter Samuel in Argentina's upcoming Group B match against Greece could deny Argentina's defence one of its most experienced and solid players.

Samuel limped off Thursday's 4-1 victory against South Korea in the 22nd minute with an apparent thigh problem and was replaced by Nicolas Burdisso. The Inter Milan centre back is expected to undergo medical tests Friday.

"It's been confirmed that Samuel suffered a cramp in his left thigh," Argentina team spokesman Andres Ventura said. "He is being evaluated day by day. It's not a serious injury ... but it's too soon to say whether he will be available to play against Greece."

Samuel did not practise with the rest of the team Friday at the University of Pretoria, instead undergoing physical therapy sessions to treat his injury.

Veron, meanwhile, played in a training game against a team of mostly Argentina youth players. He iced his right leg after the practice but seemed to show no signs of his ailment while playing in his usual midfield spot.

Argentina coach Diego Maradona has opted for caution before, preferring to sit Juan Sebastian Veron against South Korea after the veteran midfielder left the game against Nigeria with an ailing right calf.

Burdisso, Samuel's former Inter teammate who is now on loan to AS Roma, provides flexibility for Argentina as he has experience in the middle and as a fullback, but Diego Maradona's defence is also under threat from yellow cards picked up by Gabriel Heinze and midfielder Javier Mascherano against South Korea.

Further limiting Maradona's options, Jonas Gutierrez will miss the match against Greece after being shown yellow cards in Argentina's first two games.

Normally a midfielder, Maradona prefers to position Gutierrez on the defence's right side with the option to go on the attack. The task seemed to overwhelm the Newcastle player during the 1-0 win over Nigeria, although he improved in Argentina's second match.

Argentina needs just a draw against Greece to advance to the knockout round.