As a result, the Royals' catcher will undergo surgery to repair extensive damage in his right rotator cuff on Friday and will miss the rest of this season. He is expected to be out eight to 10 months.
The severity of the injury was revealed in an MRI on Monday. The surgery will be performed in Los Angeles by Dr. Neal ElAllatrache.
Backup Brayan Pena started at catcher on Wednesday night against the Rangers for the second straight game. He will divide the catching duties with rookie Lucas May, just brought up from Triple-A Omaha.
Although Royals manager Ned Yost said he hoped to have Kendall back "by the spring," even just eight months would carry through the first month of the 2011 season in April. Kendall will be in the second year of his Royals contract.
Kendall started 118 of the Royals' 132 games. He was an iron man behind the plate, missing just five of 90 games to the point where he was injured on July 17, sliding into second base on a steal in the first inning against Oakland at Kauffman Stadium. Even then, he continued to play regularly.
"We gave him a cortisone shot, it felt better and we went to Oakland two weeks later and he had a check swing and that's when he totally tore it," Yost said. "We decided now is the time to do it so, hopefully, it gets him ready to go by the end of Spring Training for Opening Day."
Kendall, who became the Royals' No. 2 batter in the lineup, was hitting .256 with 18 doubles and 37 RBIs. Behind the plate, he was credited with throwing out 31 of 131 would-be basestealers, or 21.7 percent.
"His throwing percentage is still remarkable when he got to the point where he couldn't even raise his arm. He was catching and would have to take his glove to push his arm back into a throwing position and was still throwing runners out," Yost said. "It just shows you the mentality and the makeup of Jason Kendall. I think he would have played out the year if the training staff hadn't just hog-tied him and made him have an MRI."
Pena this season had started just 14 games at catcher prior to Wednesday night. May had no Major League experience at all.
"Pena will probably play four days a week and Lucas May might play three. Brayan may play five and Lucas two," Yost said. "And there'll be weeks when Lucas will play four and Brayan will play three. We'll kind of just mix it up and get a good look at both of them."
It's possible another catcher could be brought up from the Minors later, he said.
Kendall was stubborn about staying off the field and eventually giving in to surgery.
"He was very stubborn with the trainers, just 'Don't dig, don't poke, don't pull, just get me ready to play,' " Yost said.
Finally head athletic trainer Nick Kenney talked him into Monday's MRI.
"He tore his rotator cuff and it curled back in there. It just amazes me, the toughness of this kid," Yost said.
"In Cleveland, he threw out two of three runners, but he literally couldn't lift his arm anymore. It got to where he was catching the ball and his glove literally was pushing his hand up. Once he got it up, he could throw it. And he'd push his hand up on his bat so he could swing. They just don't make 'em like that anymore."
Kendall's season is over but ...
"He'd be playing today if it was up to him," Yost said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.