After a short talk with catcher Rod Barajas and trainer George Poulis, Halladay's night was over in the fourth inning -- ended by a strained right groin.
The bullpen was left to pick up where Halladay left off, but couldn't hold down the Marlins. An eighth-inning meltdown that included a grand slam by Marlins center fielder Cody Ross sent the Jays to a 7-3 loss to Florida on Friday at Rogers Centre.
Marlins right fielder Jeremy Hermida, who led off the fourth inning, saw two pitches from Halladay before the Jays' ace determined he could go no further.
"Really, just kind of out of nowhere I felt it on one pitch," Halladay said. "It wasn't a lot of pain right after, so I was kind of hoping it was just a twinge or something. But, I felt it on the next pitch. It's just one of those things that kind of out of nowhere catches you off guard."
Halladay's early exit brought to an abrupt halt a meeting the Marlins had been waiting for.
"We've been talking about facing Halladay for about two weeks," Ross said. "We matched it up, and we thought we were going to get him on the first day. Everyone was talking about it."
Halladay left with the Jays behind, 1-0, but a pair of RBI singles by left fielder Joe Inglett and second baseman Aaron Hill took Halladay off the hook for the loss.
Richmond was able to finish off Hermida -- completing a strikeout that Halladay started -- and pitched 3 2/3 innings after Halladay's departure.
"He kept us in the ballgame," Blue Jays manager Cito Gaston said of Richmond's outing. "He's done that in the past -- even when he's started."
With the Jays ahead, 2-1, the Marlins tied the game in the seventh on a run charged to Richmond, when a single by shortstop Hanley Ramirez with Brandon League on the mound scored an inherited runner.
Things would get worse for League in the eighth, though, when Hermida sent a belt-high fastball from League rocketing to the outfield. Center fielder Vernon Wells tried to make a leaping grab, but couldn't come up with it, as the ball bounced off the wall, and Hermida made his way to second base.
League then walked Marlins second baseman Dan Uggla. The next batter up, catcher John Baker, was hit in the leg with a 95-mph fastball, loading the bases.
It was then that Ross hit an 0-2 offering from League deep into the stands, cashing four runs to give the Marlins a 6-2 lead.
"It looked like a splitter that stayed up," Gaston said of the pitch that put the Jays away. "That's what it looked like to me."
While a lot of the Marlins' hits up until the eighth inning came on infield singles that the runners barely legged out, there was no doubt about Ross' grand slam, which went to the deepest part of the outfield.
"They're base hits, and they got them at the right time," Gaston said. "To start the game, the first run they got, they didn't hit that ball hard. The run that tied the score up -- didn't hit that ball hard. But, hey, the home run was hit hard."
Still, the loss could be the least of the Jays' worries, depending on the severity of Halladay's groin strain. Toronto's rotation has already been crippled by injury -- Casey Janssen started the year with shoulder problems, Ricky Romero missed time with an oblique strain, Dustin McGowan and Shaun Marcum are recovering from surgery and aren't expected to return soon and Jesse Litsch learned last week that he will need to undergo Tommy John ligament replacement surgery on his right elbow.
Halladay saw team doctors after leaving the game, iced the injury and had other treatments. He will be examined by doctors soon -- possibly on Saturday -- and will get an MRI exam if necessary.
If Halladay misses a start, Richmond -- who was not scheduled to start a game until June 20 in Washington -- will likely take Halladay's spot in the rotation.
Halladay said it was not a problem he'd had in the past, and he did not see any signs that he might be hurt until the fourth inning.
"It wasn't anything that felt tight before that or would've given me any signs," he said. "It just kind of showed up quickly, and I don't know -- it was kind of out of nowhere.
"It's kind of tough when those things sneak up on you, and you don't really know why or what could have led to it. You just deal with it and try to make the best out of it and move forward."
Erika Gilbert is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.