"He's just gaining strength in that shoulder. He was really pushing early, but I think now that we've got Treanor, he feels better about where we're at," manager Ned Yost said.
"So he's just now doing it right and getting it strong."
Kendall is likely to stay in Kansas City to work with physical therapist Jeff Blum while the Royals go on the road this weekend. There's no set timetable for Kendall's return, which previously had been somewhat vaguely late April or early May. When ready, he'll play rehabilitation games in the Minors.
"He really looked good in batting practice yesterday," Yost said. "He's making progress."
Kendall had extensive surgery on his right shoulder on Sept. 3.
"When he can make good, strong throws to second base three or four days in a row, he'll be ready to go play," Yost said.