Marmol, sidelined since May 12 with a strained right hamstring, will throw on the side Monday for Iowa, then throw a simulated game Wednesday, and, if all goes well, he'll get into a Minor League game Friday.
Clevenger, out since April 26 with a strained right oblique and rib cage injury, has been taking batting practice this weekend for the first time since he was injured. He will play Tuesday and ease his way into game action, gradually working up to nine innings as the week progresses.
Welington Castillo has a mild sprain of the MCL in his right knee, and is expected to miss four-to-seven days, depending on how he responds to treatment. He was injured on Friday on the last pitch Kerry Wood threw.
"I felt like I couldn't bend my knee or go side to side," Castillo said of the injury.
He hopes to resume baseball activities on Wednesday.
Reliever Blake Parker, who came out of Saturday's game, underwent an MRI on Sunday which showed he has a mild right hamstring strain. Parker is listed as day to day.