TORONTO -- For a three-game series that starts in Toronto on Monday night, the Red Sox will be without two players who have been key cogs to their June surge in righty Tanner Houck and center fielder Jarren Duran, who were both placed on the restricted list.

Red Sox manager Alex Cora confirmed last week that Houck and Duran aren’t vaccinated against COVID-19.

In place of Houck and Duran, right-hander Connor Seabold, scheduled to start in the opener, and infielder Yolmer Sánchez were called up from Triple-A Worcester.

Prior to the start of the 2022 season, Canada’s restrictions on allowing individuals unvaccinated against COVID-19 into the country led MLB and the MLB Players Association to agree to permissible roster modifications for games in Toronto. There is no required minimum or maximum stay on the restricted list.

Houck should be back in action on Friday, when the Sox open a three-game series at Wrigley Field against the Cubs. Duran is expected to return then, too, unless Kiké Hernández returns from his strained right hip flexor ailment before then.

With Houck (6-for-6 in save opportunities) emerging as the closer for a bullpen that had lacked stability and Duran (.327/.386/.500 in 13 games) becoming a force in the leadoff spot in place of the injured Hernández, the Sox are 19-4 in June and have won seven in a row.

Houck also missed Boston’s four-game series in Toronto from April 25-28, when the club lost three out of four. Duran was at Triple-A Worcester at that time.