Montoyo tabbed Jacob Waguespack to enter the game, but the righty was eventually deemed ineligible because he wasn't on the lineup card for Toronto's contest against the Atlanta Braves.
Toronto optioned Waguespack to its taxi squad earlier in the day in order to shave the active roster to 28 players. The team subsequently recalled the 26-year-old after placing starter Trent Thornton on the injured list with elbow inflammation.
The only problem: Waguespack apparently wasn't included on the lineup cards delivered to the umpires, bringing a bizarre end to a whirlwind day for the Blue Jays reliever.
Adding to the confusion, an official MLB rule apparently indicates Waguespack's inclusion on the lineup card wasn't required for him to be eligible to play:
Montoyo said afterward he had no idea why Waguespack wasn't on the umpires' lineup cards after the Blue Jays submitted their lineup digitally.
"It was on all our cards," Montoyo said, according to Sportsnet's Shi Davidi. "For some reason, the ones they had, (Waguespack) wasn't on it."
The Blue Jays went with right-hander Rafael Dolis in Waguespack's place.
Braves skipper Brian Snitker, meanwhile, expressed concern for Atlanta starter Touki Toussaint, who was forced to sit in the dugout for longer than usual due to the delay.
"I don't know how all that works. I don't like that though. ... I don't want a kid (Dolis) to get hurt because of some clerical error," Snitker said, according to Keegan Matheson of MLB.com. "But there's something that has to be done because that's not fair to Touki to leave him in the dugout for an extended period because of a clerical error."