At the center of the feud is one of the most bizarre scandals in recent baseball memory.
Multiple players on the Royals suggested that the Blue Jays have been stealing sandwiches from the visitors' clubhouse in an effort to gain a competitive advantage over their opponents.
"It's just not cool," said Royals third baseman Mike Moustakas. "I come in to the clubhouse every game day and have a turkey, bacon and swiss sandwich with a spread made from fresh sun-dried tomatoes. It's delicious, and it really helps me get in the right mindset for the game."
"Without my sandwiches, man, I'm ruined. I can't think straight."
Moustakas was held out of the Royals' lineup on Saturday and Sunday, presumably due to a minor injury sustained during the series. Talk to him, though, and you'll get a different story.
"Physically, I'm fine," Moustakas said. "Mentally? Emotionally? I'm a wreck."
Sources with the Royals indicate they first became aware of the situation right before the game on Thursday, when only twenty sandwiches were delivered to the team - nowhere near enough to feed the players and staff.
After a similar situation the next two nights, the team suspected foul play.
"How do you think they hit all those home runs?" Moustakas demanded. "There's no way they can do that on their own. They must have had some extra protein involved in their diet, and the only possible explanation is that they were stealing our sandwiches."
Starting pitcher Yordano Ventura may have suffered the worst of sandwich-stealing.
Before making his start on Satuday, Ventura—who notably hates tomatoes—was forced to eat a vegetarian sandwich after his usual lunch went missing. After Ventura gave up back-to-back home runs in the fifth inning, fans began to point out the possibility of sandwich stealing.
"He (Ventura) just doesn't look comfortable in the stretch," said one anonymous fan. "That's a sure sign of someone who didn't have a proper pregame meal."
Tempers flared in the final game of the series on Sunday, when Royals pitcher Edinson Volquez repeatedly pitched high and inside to Blue Jay Josh Donaldson.
"He stole my sandwich!" Volquez said after the game. "I saw him steal my sandwich, and I had to send a message that stealing sandwiches is not okay."
Toronto has a history of stealing sandwiches, and were notably suspected of doing so in 2010 when a man in white was seen carting an order of several dozen barbecue sandwiches into the outfield seats.
But Brett Lawrie, formerly with Toronto and now with the Oakland Athletics, thinks that the Royals were overreacting.
"They're always looking for something to complain about," Lawrie said. "They did earlier this year and they're doing it again. Accusing someone of stealing sandwiches? What a disgrace to baseball."
"When I come back to Toronto with the A's, there's never any shortage of my favorite type of sandwich—hot dogs!" Lawrie added.
As the Royals boarded their team plane and headed back to the United States, many of the players were still upset by the weekend's events. However, one player in particular did not seem fazed.
"I only eat an organic, nutritious paste for my meals," said Royals left fielder Alex Gordon. "Sandwiches are frivolous."
"It's far healthier, and it gives me more time to rehab my groin," Gordon said, staring intently at his injury as if mentally willing it to get better. "I'm already a week ahead of schedule, and if I can concentrate harder, I should be back by the end of August."