Marks has a torn anterior cruciate ligament in his right knee. Tests on Monday revealed the extent of the damage.
Marks, one of the Jacksonville Jaguars' top defensive players, injured his knee in Sunday's season finale at Houston. He will have surgery after the swelling subsides and will miss the entire offseason but hopes to return during training camp. He finished with 44 tackles, 16 quarterback hurries and a career-high and team-leading 8 1/2 sacks. His last sack, which came on the final play against Tennessee on Dec. 18, triggered a $600,000 bonus in his contract.