The Kazakh rider Andrej Kashechkin was sacked by the Astana team yesterday after his B sample tested positive for blood doping.
"After having been suspended following the A sample results, Kashechkin has been sacked with immediate effect," Astana said.
Kashechkin failed a random test on 1 August in Belek, Turkey. Under the International Cycling Union's (UCI) anti-doping charter, the 27-year-old faces a two-year ban from the sport and a fine equivalent to one year's salary.
The Kazakh rider left the Tour de France before the start of the 16th stage in July after his team pulled out of the race following his compatriot Alexander Vinokourov's positive test for a similar offence.
Both riders have failed a test for homologous blood doping, a method using blood from another person. Vinokourov, who was subsequently sacked by Astana, denies any wrongdoing. He tested positive after an impressive victory in the 15th stage of the Tour, a time trial in Albi.
Astana suspended their activities last month, but will resume racing tomorrow at the Grand Prix de Plouay, a Pro Tour race. The German rider Andreas Klöden is a major doubt for the race after sustaining hand and hip injuries when he was hit by a car while training on Thursday.
Alejandro Valverde will remain on the Spanish roster for the Road World Championships despite being banned by the UCI.
"We're going ahead with Valverde, until at least someone advises us not to," said the Spain coach, Francisco Antequera. "Alejandro passed a control in the preselection ... nothing has changed in the slightest."
The championships take place in Stuttgart, Germany, from 26 to 30 September. The UCI banned Valverde on Wednesday and wants an inquiry into the rider's alleged involvement in the Operation Puerto doping scandal.
The Spanish cycling federation president, Fulgencio Sanchez, said he was not ready to open proceedings since no new evidence from the doping scandal had been introduced since last year.