According to the Dodgers, Ellis had a 30-minute clean-up procedure to debride tears to the medial and lateral cartilage. He will begin physical therapy next week and begin baseball activities in six weeks.
"A little clean-up," Ellis said via text message. "I'll be fine."
The previously unreported injury might help explain Ellis' 0-for-30 slump in September.
This was Ellis' first full season with the Dodgers, and he was one of the more pleasant surprises, establishing himself as an everyday starter by hitting .270 with 13 home runs (more than in any of his Minor League seasons) and 50 RBIs while playing in 133 games.
The 31-year-old caught 131 games and threw out 28 potential base stealers, fourth in MLB in both categories. As he has throughout the year, Ellis showed a keen eye at the plate and led the team with a .373 on-base percentage.
More importantly, he won over management with his work ethic and ability to adhere to the pitching game plan, as the Dodgers' staff finished with a 3.34 ERA.
Ellis is the 11th Dodger to undergo surgery this year. Among those is Matt Kemp, who underwent left shoulder surgery on Friday and will be sidelined for three months.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.