Evans accepted he had stamped on England scrum-half Harry Ellis during the European Cup defeat to Leicester Tigers and will be out of action until February 20 as a result.
It means he will miss four Celtic League games for the Ospreys and will be unavailable for the first two games of Wales' RBS 6 Nations campaign, against England and Scotland.
Ellis will require surgery on his knee as a result of the incident but the injury is not as serious as first feared and he hopes to be back in action in time for Leicester's next European Cup match against Stade Francais on January 15.
Both parties were advised of the right to appeal.
