The team opens camp on Friday, but the four players won't be eligible to return until late next week at the earliest.
The Phillies had seven players test positive for COVID-19 last month, but manager Joe Girardi couldn't answer whether any of the players were among them because of medical privacy.
"What I can tell you is they're on the injured list, and that's about all I can tell you," Girardi said Thursday. "MLB has given protocols on how to handle it. I don't have a timetable on those players. I can't really answer that question. As soon as I get an answer, I will give it to you."