Busch had a two-year ban lifted by Switzerland's highest appeals court in November. The ban had been imposed by the Court of Arbitration for Sport after Busch refused to take a drug test because he was at home relaxing with his girlfriend when the testers arrived unannounced. He took -- and passed -- the test several hours later.

On Tuesday, the 24-year-old forward signed the pledge. It's required by the National anti-Doping Agency for all Olympic team members.