"I don't have an exact schedule. Look, we're excited for him to go out there and play four or five innings, get a few at-bats. Kind of run the Spring Training process with him a little bit."
Cash allowed that Duffy has been doing a lot of work at Tropicana Field.
"You could probably make the argument that he's done enough stuff here as far as getting his body into shape," Cash said. "But there's something to be said for getting on the field, standing out there for four or five or six innings, whatever it is. And we'll do a gradual buildup."
Duffy believes the rehab will take approximately two weeks.
"I think that's kind of the tentative plan," Duffy said. "As with anything, it always depends on how I'm feeling day to day. So add or subtract several days if need be. I'm really happy about the way [his recent workouts, including Monday's, have gone]."
Duffy has dealt with heel problems for several years, so he said he's looking forward to playing baseball without the pain.
Cash noted that it is to be determined if he'll spend his entire rehab with Charlotte.
"Right now, Port Charlotte looks like a fairly favorable schedule," Cash said. "I know they play some games in Clearwater, and then they go to Port Charlotte."
The Rays acquired Duffy in the four-player trade that sent Matt Moore to the Giants on Aug. 1, 2016. Duffy took over as the starting shortstop after the deal and he did not make an error in 18 games (55 chances and 153 innings) at the position. He hit .276 with a home run and seven RBIs before having season-ending surgery in Charlotte, N.C., to remove the bursa from the heel and debride the bone abnormality.
Bill Chastain has covered the Rays for MLB.com since 2005. This story was not subject to the approval of Major League Baseball or its clubs.