TORONTO -- As the injury bug continues to trouble the Rangers roster, more adversity struck early in the club’s 7-3 loss to the Blue Jays on Sunday at Rogers Centre.

Staring down the barrel of a three-game sweep, the Rangers turned to starter Jon Gray, fresh off a quality start in his last outing. But Gray tweaked his lower body on one of his final warmup pitches prior to the first inning and called out the trainers.

Gray chatted with manager Bruce Bochy, who removed his starter before the inning began with what the club called “right groin tightness.” That’s notable, as Gray missed two weeks in late May and early June with the same injury.

“It feels like a bad dream,” said Gray, who felt a pinch in his groin during the pregame bullpen but tried to pitch through it. “Knowing the team needed a big game from me and not even being able to throw a pitch, it sucks.”

Gray will undergo imaging in the coming days to determine the severity of his injury, and his early exit cast a shadow over the remainder of the contest. The right-hander’s replacement, Jonathan Hernández, immediately surrendered three runs in Gray’s stead. By the third inning, Toronto’s lead swelled to 6-0, a deficit the Rangers never closed.

For context, Texas’ impromptu bullpen day comes after starter Michael Lorenzen recorded just two outs on Saturday -- the shortest start of his career -- leaving the Rangers’ relief corps to soak up 7 1/3 innings.

And so the Rangers had to get creative. With longmen José Ureña and Dane Dunning unavailable, having mopped up most of Saturday’s innings, Lorenzen volunteered to warm up and enter in the fifth inning, the right-hander’s second appearance in as many days.

“Once [Gray’s injury] happened, [Lorenzen] came down and volunteered to pitch,” said Bochy. “He goes, ‘I threw 40 pitches yesterday. I'm good to go. I can help out.’”

Lorenzen has spent most of his career as a reliever, no stranger to short-notice appearances, but this weekend’s schedule was a first for him. He’d never started a game one day, then pitched in relief the next, not even in college at Cal State Fullerton.

Lorenzen knew how badly his club needed innings, though, and with revenge on his mind from the previous game, he stepped up.

“I think when you're not expecting it, being out there kind of helps because you go in a little bit of a fight or flight, and your body warms up quicker,” said Lorenzen. “And then you just know you’ve got to fill up the zone and eat as many innings as you can.”

Lorenzen performed adequately despite the surprise nature of his appearance, tossing four innings of relief and allowing one run on three hits. His fellow pitchers, especially Gray, appreciated the heroics.

“I absolutely loved that,” said Gray. “That was huge for us, and it's gonna help us out for the next couple [games].”

The Rangers had a second near-miss on the injury front in the eighth inning, when Josh Smith fouled a ball off his left knee and crumpled into a heap at the dish. After a breather and a visit from the trainer, Smith dug back in and smashed a towering two-run homer to right field, his 11th blast of the season.

On a big-picture scale, Gray’s injury, should he miss significant time, marks another disappointing development for a Rangers crew decimated by injuries. While starters Tyler Mahle and Jacob deGrom are close to a return, Gray has been a rock in the rotation this year, tossing 94 innings over 20 appearances with a 3.73 ERA.

Now Texas departs Toronto, disappointed after suffering a sweep to the Blue Jays, who sit in last place in the AL East and made three trades over the weekend as their sell-off begins. Bochy lauded his club’s resilient mentality as the Rangers gear up for a tricky three-game road series against the Cardinals beginning Monday.

“You're gonna hit bumps in the road,” said Bochy. “This was a tough [series] … You’ve got to keep fighting. You don't have a choice in his game, as I say, and you’ve got to keep going.”