Patrik Sinkewitz has been dismissed by the T-Mobile team after withdrawing a request to have his B-sample tested.
Sinkewitz's was the first drugs case to hit this year's Tour
The German cyclist was suspended after it emerged during the Tour de France that he tested positive for elevated levels of testosterone on 8 June.
Sinkewitz revealed on Tuesday that he had used a testosterone gel in training and said he accepted the test result.
"It was a big mistake and irresponsible toward my team, colleagues, the sponsor and the whole of cycling," he admitted.
Sinkewitz, 26, said he had used the gel on his upper arm "without thinking, or simply in great stupidity, on the evening before the doping test".
After he declined to have his B-sample tested, T-Mobile spokesman Christian Frommert said: "For the team, this means that it is a positive doping case - that means he will be fired."
Ahead of the Tour de France, Sinkewitz had, like all competitors in the race, signed the International Cycling Union's new anti-doping charter.
It commits riders to promise that they are not involved in doping and agree to pay a year's salary on top of a two-year ban if caught doping.
Sinkewitz added: "I could have achieved my performance without (drugs)", and pledged to help bring about "a new cycling without doping" in future.
Astana have suspended their activities for one month after sacking lead rider Alexandre Vinokourov for failing a Tour de France blood doping test.
The Swiss-based, Kazakhstan-backed team said in a statement: "Following recent events, we have decided to stop our activities until the end of August.
"This period of time will be the opportunity for deep questioning."