Lourdes, France – RadioShack's Tour de France hopes suffered a huge blow on the second day in the high mountains when Andreas Kloden pulled out during Friday's 13th stage.
RadioShack, the last professional team of Lance Armstrong, were left reeling after a dramatic first week when Janez Brajkovic and Chris Horner both left the race due to injuries.
Kloden, who finished runner-up to Armstrong in 2004, sustained a lower back injury in a crash on the ninth stage on Sunday.
Having dropped further out of contention during the climb to Luz Ardiden on Thursday, he lasted barely an hour on the 13th stage before throwing in the towel.
He is the team's fourth abandon. Ukrainian Yaroslav Popovych pulled out suffering from a fever on Tuesday.
Half an hour after Kloden's withdrawal, Dutchman Lars Boom stepped off his bike and into his Rabobank manager's car.
His retirement is a further blow to the orange and blue Dutch outfit, whose main yellow jersey hope Robert Gesink has been underperforming since suffering a back injury last week.
Russian Vladimir Isaichev, who rides for Katusha, also pulled out during the stage.
Katusha were dealt a blow on Monday when it was revealed Alexandr Kolobnev had tested positive for a banned diuretic and he quit the race in digrace.
After losing young sprinter Denis Galimzyanov on Thursday, after he finished outside the stage 12 time limit, and Russian champion Pavel Brutt on stage nine, Katusha have now lost four of their nine starters.
Friday's stage is a 152.5km ride from Pau to Lourdes and includes the climb of the Col d'Aubisque. – Sapa-AFP