Germany coach Joachim Low has expressed his disappointment with Kevin Kuranyi after the striker appeared to walk out on the national team on Saturday.

The Schalke forward left the Westfalenstadion during the interval of Germany's 2-1 win over Russia after being left out of the 18-man squad.

Reports in German newspaper Bild say the 26-year-old may now announce his international retirement.

Low admitted he had been unable to make contact with the player since Saturday evening.

"We were all surprised by Kevin Kuranyi's early departure and, despite numerous efforts, neither myself nor Oliver Bierhoff have been able to reach him by telephone," Low told www.dfb.de, the official website of the German Football Association.

"We need an explanation and then we will comment further."

Low also revealed Kuranyi had spoken to him before the game to let the coach know how disappointed he was at missing out on a place in the squad.

Patrick Helmes was picked ahead of Kuranyi as the only striker on the bench.

"As we had the team meeting on Saturday lunchtime, when I named the team for the Russia game, Kevin came to me immediately afterwards and expressed his disappointment at not being part of the 18-man squad," Low explained.

"I can understand his disappointment, but the reaction in the evening is unacceptable.

"We have 20 top men with the national team and we coaches always have to take tough decisions."

Kuranyi has made a total of 52 appearances for Germany, scoring 19 goals, but has recently fallen behind Miroslav Klose, Mario Gomez and Lukas Podolski in the pecking order.