The Blue Jays reinstated shortstop Munenori Kawasaki from the paternity list and optioned right-hander Thad Weber to Triple-A Buffalo on Monday.
Weber will stay with Toronto, however, as the club will recall him as its designated 26th man for the doubleheader against the Yankees on Tuesday.
While the Blue Jays traveled to St. Petersburg for a weekend series against the Rays, Kawasaki returned to Toronto to be with his wife as she gave birth to a baby boy on Friday. The plan all along was to have Kawasaki return for Tuesday's doubleheader, even when Jose Reyes was sidelined by a sore right knee on Sunday.
Toronto recalled Weber from Buffalo on Tuesday, but he hasn't pitched since then. In two stints with the Blue Jays this season, Weber has given up one run on four hits in four innings spanning four appearances.
Weber, 28, was claimed off waivers from the Padres in May, and he has put together a 6-4 record and a 2.63 ERA in 15 appearances (12 starts) for Buffalo.
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry.