Hendrickson had been 1-4 with a 6.35 earned run average in seven starts this season. Left-hander Rich Hill, who has been on the disabled list with a strained left elbow, could be a candidate to make the Saturday start.
Asked specifically about Hill's status, Trembley said, "He's getting close."
Regarding the status of injured outfielders Luke Scott (bruised left shoulder) and Adam Jones (mild right hamstring strain), Trembley said both players are making progress.
"Scott is better," Trembley said. "He said he's about 60-65 percent. He's not able to take live batting practice yet. He's just hitting off a tee. Jones is much improved. I would say Jones is closer to playing than Scott right now."
Robert Falkoff is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.