Coach Jason Garrett said Lee is scheduled for surgery on the torn anterior cruciate ligament in his left knee Thursday. Garrett isn't saying whether Lee will try to play in 2014.
Lee was injured during 11-on-11 work on the first day of offseason practice last month. If the Cowboys think he can make it back, they could delay a decision on season-ending injured reserve until during the season.
The normal recovery time on ACL surgery is at least six months.
Lee has missed 15 games the past two seasons because of toe, hamstring and neck injuries.
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