Price, who was placed on the 10-day DL on July 28 with elbow inflammation, threw a 60-foot flat-ground session on Tuesday and was moved to 90 feet on Wednesday.
The Red Sox have not set an official day for Price to return to throwing activities.
"It's more of a kind of day-to-day situation and where he feels," Farrell said. "When he's feeling as he did for a couple of days, he came in and threw. He's backing off of it right now."
If there is any bit of good news sprinkled in the update, it's that the soreness in Price's arm isn't in a specific area that would be the cause for more alarm.
For the Red Sox, the fact that Price was scheduled to throw three times in the week wasn't supposed to be any indication of his imminent return. As of now, the team has given no clues as to when Price will be back in the rotation.
"You're always optimistic for anyone." Farrell said. "But I don't know that we ever had a date that we were penciling in for his return."
• Farrell says that reliever Joe Kelly, who is expected to be activated from the disabled list on Saturday, will be slowly integrated back into his spot in the bullpen.
"He'll be in some low-leverage situations trying to get back into the flow of things," Farrell said. "I can't say how many that would be. That's dependent on score, who's available, that type of thing. The fact that he's healthy is number one."
• Reliever Carson Smith will throw an inning for Double-A Portland on Saturday. Smith underwent Tommy John surgery in May 2016.
• Second baseman Dustin Pedroia took part in baseball activities on Friday for the first time since being placed on the DL on Tuesday. Farrell says he will start swinging on Saturday.
Evan Chronis is a reporter for MLB.com based in Boston and covered the Red Sox on Friday.