Hendriks was designated for assignment on Wednesday to make room for starter Ubaldo Jimenez on the 40-man roster. He walked through the clubhouse this morning, but his locker remains empty.
His uniform could return to it later today.
Miguel Gonzalez will throw 35 pitches in today's bullpen session after totaling 25 on Wednesday. If his back responds favorably, he will throw to hitters tracking pitches on Sunday.
Kelvin De La Cruz also will throw 35 pitches today in his session.
Suk-min Yoon was pleased with yesterday's bullpen session, his first with the Orioles.
"I threw nice and easy. My control was good and it was better than I expected," he said through interpreter Justin Yoo.
"I'm on pace and everyone's been very welcoming, so that's also helped me get on pace."
Yoon will return to the mound on Saturday. No hitters. Same setup as yesterday.
Yoon, who throws a fastball, slider, changeup and curveball, appears comfortable in his new surroundings.
"This is my first spring training here, but baseball is baseball anywhere you go," he said. "You have some of the best players here. Spring camp has been very good."
Yoon hasn't been told whether he'll work as a starter or reliever in camp. However, executive vice president Dan Duquette said the club initially wants to evaluate Yoon as a starter.