Cora had been playing with a torn ligament in each thumb since June. He injured the right thumb on May 17 in San Francisco and was placed on the disabled list after that game.
Cora revealed on Monday that he had torn the ligament in the left thumb a day earlier but felt that he could play through that pain. After a two-week stint on the DL, he returned to play in 56 games before deciding that the pain was too much to overcome.
"It's hard enough to hit with two hands," Cora said. "I can't be disappointed, especially knowing the left one was like that, too. Looking back, I'm very proud of what I tried to accomplish in trying to help this team to win. I've got to take care of myself."
Cora did add that had the Mets been in the middle of a playoff push, he might have tried to play through the pain a little longer.
In all, Cora played 82 games this season at second base and shortstop, batting .251 with one home run and 18 RBIs. He becomes the third Mets' shortstop to hit the DL, after Jose Reyes and Ramon Martinez. Overall, he is the 12th Met on the DL.
"Every week, somebody is going down," said a dejected Livan Hernandez after hearing about Cora's injury. "We've got to fight and keep working and win some games."
Cora hopes to be completely healed by the beginning of December.
Tim Britton is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.