Patrick, one of the Flyers' young stars, didn't play a single game during the 2019-20 season due to an ongoing battle with a migraine disorder. He wasn't included on the team's training camp roster as part of Phase 3 of the NHL's return-to-play plan.
"Our focus is on getting him ready for the 2020-21 season. We want to be prudent and prioritize his health and safety in the long run," Fletcher said. "We have a short runway here before we jump right into playoff hockey."
Both Fletcher and Patrick previously expressed optimism that the 21-year-old would be able to return this season.
Patrick was selected second overall in 2017 and has amassed 26 goals and 35 assists in 145 games.
The Flyers will compete in a round-robin tournament that will determine the top four seeds in the Eastern Conference before a traditional 16-team playoff bracket begins.