Coach Bruce Boudreau said Ovechkin has been hampered by the problem for months.
General Manager George McPhee said the sixth-year player needs time to heal completely.
The 25-year-old Russian has 29 goals and 77 points in 73 games.
Washington will play four of its nine remaining regular-season games in the next 10 days. The Capitals are two points behind Eastern Conference-leading Philadelphia. The two teams play Tuesday.