MOSCOW (Reuters) - Former world number one Marat Safin has pulled out of Russia's team for this month's Davis Cup semi-final against Argentina in Buenos Aires.

World number 39 Safin cited personal commitments as he attempts to climb the rankings. He is due to play at the Thailand Open immediately after the September 19-21 tie in Argentina.

"(Safin) needs to keep getting points before the end of the year and feels the trip from Buenos Aires to Bangkok would be very long and tiring," his personal website www.maratsafin.com said.

Safin said he had talked to Russia captain Shamil Tarpishchev, receiving permission to miss the semi-final.

The Russians were already weakened by the absence of 2002 Davis Cup hero Mikhail Youzhny, who has not regained top form after missing the U.S. Open with a neck injury.

They will have to rely on world number six Nikolay Davydenko, 20th-ranked Igor Andreev, Dmitry Tursunov (26) and newcomer Igor Kunitsyn, who is ranked 76 in the world.

Russia, who reached the final last year, are bidding for their third Davis Cup title after winning in 2002 and 2006.

(Reporting by Gennady Fyodorov; editing by Clare Lovell)