The Red Sox can’t seem to figure out the Blue Jays, and a disastrous third inning sunk them again Tuesday

At the start of a stretch filled with urgency, the Sox instead had to turn to rookie Josh Winckowski, summoning the righthander back from Worcester. Winckowski couldn’t get out of the third inning, as the Blue Jays erupted for an eight-run rally that laid the groundwork for a 9-3 blowout victory.

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The Red Sox struck first, scoring a run when Christian Arroyo led off the second inning with a double off the wall and Kiké Hernández got on top of a 92 mile-per-hour elevated fastball from Jays starter Ross Stripling to put the Red Sox ahead, 1-0. The advantage proved fleeting, tauntingly flickering out of existence.

A massive Blue Jays rally coalesced sneakily. Though Jackie Bradley Jr. – warmly greeted with a tribute video and applause in his first Fenway at-bat as a visitor – led off the third with a double off the scoreboard in left (one on which Tommy Pham injured himself while crashing into the wall), Sox starter Winckowski quickly recorded back-to-back groundouts, with Bradley remaining stuck at second.

Winckowski seemed to have the inning under control, jumping ahead of Lourdes Gurriel Jr., 1-2. But with two strikes and two outs, Winckowski saw the game unravel over his next 16 pitches.

Gurriel crushed a slider to right for an RBI double. Winckowski missed the strike zone with his next seven pitches, issuing a four-pitch walk and then falling behind Teoscar Hernández. Hernández ripped a 3-0 sinker for a single to center, scoring Gurriel. Bo Bichette’s eyes likewise widened at the sight of a first-pitch sinker, which he scorched to center for a single that reloaded the bases.

Winckowski then got ahead of Matt Chapman, 1-2, before missing badly outside with three straight pitches. The bases-loaded walk forced in a run and ended the rookie’s night.

“It wasn’t a conscious thought, but maybe started nibbling a little bit,” said Winckowski. “I think that’s something I’ve struggled with a little bit up here, kind of not being able to slow down the snowball. It’s obviously something to work on.

“It’s extremely frustrating. Every chance you get up here is a huge opportunity and not taking advantage of them obviously never feels good.”

Asked to keep the game in check with back-to-back lefties due up, southpaw Austin Davis proved incapable of fulfilling that mission. He allowed a two-run single to Cavan Biggio and walked Bradley to once again place three runners on base.

George Springer then popped up a pitch down the right field line, but Rob Refsnyder – newly inserted into the game following Pham’s injury – covered just 5,200 feet of the mile needed to reach the ball, and his dive proved fruitless. It bounced past him and rolled along the grandstand fence, with all three runners crossing the plate and Springer reaching third to put Toronto ahead, 8-1.

“We were one pitch away, and all of a sudden, you look up and they’ve scored eight,” manager Alex Cora said. “That’s happened a lot to us.”

Winckowski’s grim final line (six runs on six hits over 2 ⅔ innings) elevated his ERA for the season to 5.83 – coincidentally matching the Red Sox rotation’s mark against American League East opponents this year. Meanwhile, the eight-run rally added to the Red Sox’ glaring inability to finish out innings, with the team now having allowed 75 two-out runs since the All-Star break – second most in the majors in that time.

Since the introduction of the divisional structure in 1969, no Red Sox team has ever posted a winning percentage below .350 against the AL East. This year’s team is poised to challenge that standard for futility. The Red Sox are now 16-33 (.327) against the AL East, including a horrendous 3-11 mark against the Blue Jays.

That staggering disparity explains the state of the two teams’ playoff ambitions. Outside of head-to-head games, the Red Sox are 57-52, while Toronto is 55-52. The Blue Jays’ possession of a wild-card spot is a product of their season-long use of the Red Sox as a footstool.

The Red Sox, meanwhile, are fast approaching the point where even the illusion of contention is hard to sustain – particularly given the mounting injuries that seem to befall them on a nightly basis.

On Tuesday, Pham (lower back spasms) and Xander Bogaerts (mid-back spasms) both left the game. Rafael Devers (hit on the left hand by a pitch) and Arroyo (hobbled after sliding into first base to avoid a collision) both required the attention of a trainer.

By the ninth, the Red Sox looked like a team both broken and defeated, a state crystallized by the decision to employ catcher Reese McGuire to pitch the game’s final inning. Though McGuire delivered a scoreless ninth, his status as a highlight represented its own form of ignominy for a team that is 60-63.

Alex Speier can be reached at alex.speier@globe.com. Follow him on Twitter at @alexspeier.