The lengthy absence from the court led to his ranking plummeting to 30th in the world and it could drop further with his world championship final defeat to China's Chen Long disqualified by the BWF.
Lee was allowed to keep the two Asian Games bronze medals he won in Incheon, South Korea, in September as he hadn't yet been notified of his failed test.
Lee will be free to take part in the May 10-17 Sudirman Cup, one of the first events with qualifying points for the Rio Games.
The year long qualifying campaign for Rio begins next Monday.
Malaysia will be eligible to enter two singles players in the men's and women's Olympic tournaments if they are both ranked inside the top 16 at the ranking cut off.
Lee is also likely to take part in the Southeast Asian Games in June before the World Championships in Jakarta in August.
Lee, Malaysia's favourite sporting son, remains enormously popular in his homeland and was nominated last week for the country's 2014 sportsman of the year award.