The Giants announced late Tuesday that the 11-year veteran had the operation at the Hospital for Special Surgery in New York City and faces a long rehabilitation.
The Star-Ledger reported that Seubert also tore his patellar tendon as doctors initially feared. A source told the newspaper the tear was the best-case scenario because there was no cartilage damage and minimal collateral damage in the joint.
This is the 31-year-old's second major injury. He broke three bones in his right leg in 2003 and missed the 2004 season. But this season, he might have been the most valuable player on the offensive line. He started nine games at left guard and seven games at center, with Pro Bowl center Shaun O'Hara out with ankle and foot injuries.
O'Hara also expects to have surgery after meeting with doctors this week, the Star-Ledger reported.
The Associated Press contributed to this report.