PHILADELPHIA -- The Phillies changed this weekend’s rotation in St. Louis in preparation for next week’s two-game series in Toronto.

Phillies interim manager Rob Thomson flipped Zack Wheeler and Kyle Gibson, with Wheeler now pitching Friday and Gibson now pitching Saturday. That lines Wheeler up to start Wednesday in Toronto, instead of Gibson. Thomson said he will explain the decision in greater detail in St. Louis, but he added that one reason is Gibson has struggled in his last two starts and this move would give him an extra day of rest.

But the Phillies will be without a handful of players in Toronto who haven’t complied with Canada’s COVID-19 vaccination policy.

It is not known which players will not be in Toronto, but Thomson again said it will be addressed in St. Louis. Those players will be placed on Major League Baseball’s restricted list. The Phillies are allowed to replace them with players from the farm system. Those players do not need to be on the 40-man roster, and they will not need to clear waivers when they are returned to the Minor Leagues.

“You always have a concern of having a full club,” Thomson said this week.

The Phillies have encouraged players to get vaccinated as recently as a few weeks ago, when they would have needed to begin their round of shots to be ready for the trip to Canada.

“We’re always encouraging our guys,” Thomson said. “People are going to make their own choices; you’ve got to respect that.”

It will be worth watching which players the Phillies bring up from the Minor Leagues. Most likely it will be players already on the 40-man roster. Why not a top prospect? Well, if a player suffers an injury in Toronto and needs to be placed on the injured list, he would accumulate big league pay, but most important, big league service time.

So a player who is probably a year or two away from contributing at the MLB level is unlikely to get a look.