After ending his college career, Cottreau leaped to the professional ranks, signing a contract with the Albany River Rats of the American Hockey League on March 20, 2008.[2]
Cottreau spent the 2008-09 season with the Landshut Cannibals of the DEL2. He later signed with the Hannover Scorpions of the Deutsche Eishockey Liga (DEL) on June 8, 2009. On February 16, 2010, Cottreau signed a two-year contract extension with the Scorpions.[3] However, he retired from professional hockey on May 12, 2011 due to various head injuries suffered during his playing career.[1]