Monday marks the start of the second five-day increment.
"He's actually going through a lower-body lift right now, a lower-body workout," manager John Farrell said before Sunday night's game against the Tigers. "How we're approaching this post-injury is pretty much in five-day phases. It would be increased agility work, increased running. We still have to take him through some [pitchers' fielding practice], all those types of markers along the way. Optimistically, to get him on the mound in the next five days would be a really good sign."
Brian Johnson has been filling in for Rodriguez and will start Wednesday night's game in Philadelphia.
• Righty reliever Carson Smith will throw another sim game at Fenway Park on Tuesday, and the Red Sox are hopeful he will start a Minor League rehab assignment after that. The sidewinder had Tommy John surgery last May.