Sunday will mark a significant day in Rodriguez's schedule, because he can begin a steady progression of starts after that.
The Red Sox would probably want Rodriguez to pitch in six game settings (including Sunday) before activating him. Under that timetable, and if there are no setbacks, he could likely return to the Red Sox by the second week in May.
Rodriguez and righty reliever Carson Smith are two key pitchers who started the season on the disabled list. Smith, a setup man, has a strained flexor mass in his right elbow.
"Still on flat ground and will go through it this week in a throwing program that gets [Smith] out to 120 feet," said Red Sox manager John Farrell. "That will be the marker that gets him out at least a couple of times before he gets on the mound."
Smith had already pitched in five Spring Training games and he's a reliever, meaning his ramp-up back to action shouldn't be as lengthy as Rodriguez.
"Once we get into the bullpen sessions, we might take one BP and then look to get into games. We have to get through this long-toss phase first," Farrell said.