The fiery and animated hurler of the Pirates' pitching staff surrendered four runs on eight hits in only four innings of work.
But that wasn't all the pain.
Pirates manager John Russell said after the game that Snell has irritation in his right elbow and will undergo an MRI test on Monday to see what is wrong with Pittsburgh's Opening Day starter.
"Hopefully, it's not anything major," Russell said. "He didn't feel right today. If there is a little irritation in there, we need to find out about it."
Snell was the second Pirates starter to have a setback on Sunday. Lefty Phil Dumatrait was placed on the disabled list with rotator cuff tendinitis just hours before game time.
That leaves just three healthy starters -- Zach Duke, Tom Gorzelanny and Paul Maholm -- in Pittsburgh's rotation.
"It's always a concern ... when you have one of your young starting pitchers say there is something wrong with their arms," pitching coach Jeff Andrews said. "It's an immediate concern."
Snell's day started off rocky in the first when he gave up a quick two runs. Then in the fourth, left fielder Adam Lind led off the inning with a home run before center fielder Vernon Wells brought home Marco Scutaro with a sacrifice fly.
The Blue Jays made Snell work for every out and ran the right-hander's pitch count up to 91.
"There's nothing I can do about it either," a disgruntled Snell said afterwards. "I'm trying my hardest. I'm trying everything possible. My head's there, everything's there. It's just I don't know what's going [different] from last year to this year. It has nothing to do with my contract. I just don't know."
This is arguably the toughest stretch of Snell's career -- a period that has only seen one victory in 12 starts.
"Being his coach and watching him go through this has been difficult," Andrews said. "Obviously, he's not feeling healthy. He's always been a physical pitcher, a velocity pitcher. Right now, that's not happening, because of the physicality."
But Snell had a different twist on things.
"No, it's not the toughest stretch of my career," he said. "It's not going to be the last. Everybody has them. Everybody goes through it. There's probably 100 pitchers not doing well that everybody expects to do well in the big leagues. You're going to have bad years."
The Pirates tied the game at 4-4 in the bottom of the fourth with back-to-back RBI hits by Jose Bautista and Raul Chavez.
The Pirates ran into trouble again in the sixth, when reliever T.J. Beam, who was making his Pirates debut, allowed a runner to reach second. He was replaced by Franquelis Osoria, who then gave up a double to Lyle Overbay and a home run to Scott Rolen, which put the Jays up 8-4.
Pittsburgh would get another run in the sixth, but it would be too late as Jays closer B.J. Ryan shut down the Pirates with a 1-2-3 ninth to earn his 15th save of the year.
Toronto's win gave new manager Cito Gaston his first victory of the season after taking over for former manager John Gibbons on Friday.
As for Snell, he'll wait until Monday to find out if his irritation is anything serious.
"I try to fight through it and just keep on going," Snell said. "Velocity wasn't there, nothing's there. Something has got to be wrong."
Todd Krise is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.