The 29-year-old was injured while defending Arizona's Chad Williams, who caught a 22-yard touchdown pass to tie the game at 17-all. The Seattle safety’s left leg buckled as he tackled Williams in the end zone.
Thomas, whose contract was not granted an extension, had said previously he would skip some practices in protest. Unfortunately for the Seahawks, he won't be in the games, either. As he was being carted off the field, Thomas reportedly extended a middle finger toward the Seattle side.
Some of Thomas’ teammates said they understood his frustration.
"Earl wanted an extension and at the end of the day he didn't get that. It sucks to see a guy who puts his heart into something, put his all into his team and he doesn't get what he deserves."
"Earl wanted an extension and at the end of the day he didn't get that," Seahawks defensive end Frank Clark said. "It sucks to see a guy who puts his heart into something, put his all into his team and he doesn't get what he deserves."
Thomas, a three-time All-Pro, held out at the start of training camp before returning a week before the season despite not being granted an extension.
"We play a very, very emotional game," Seattle linebacker Bobby Wagner said. "I think sometimes you have to allow people to have their emotions. I don't think nothing of it. I think he has a long road ahead of him if it is the injury he is expecting."
The Seahawks recovered to win 20-17, salvaging a victory from a game in which they also lost starting tight end Will Dissly. The rookie was carted to the locker room in the first quarter with a knee injury.
Thomas had played eight seasons since Seattle selected him out of Texas with the 14th overall pick of the 2010 NFL draft.
The Associated Press contributed to this report.