Delabar, a right-hander, didn't even have time to report to the Bisons before he hopped back on a plane to join his teammates for their series finale at Yankee Stadium.
"We knew, depending on Cecil, there was a chance if something happened to Cecil, he might be the guy," manager John Gibbons said.
The decision to go with Delabar means that Aaron Loup is the only left-hander available out of the bullpen. The club could have instead gone with someone like Rob Rasmussen, who had a brief stint with the Blue Jays earlier in the year, but it decided to go with the experience.
The lack of lefties becomes a little less problematic because Delabar has fared better against those hitters this season. Left-handed batters are hitting .118 with a .420 OPS against Delabar compared to a .264 average and .903 OPS by righties.
"That's how it is, you've got Rasmussen down there, he's got very little experience," Gibbons said.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.