It could have been a momentous comeback win. Instead, it was a disastrous loss.

Now, the Toronto Blue Jays will have to bounce back against the Cincinnati Reds one day after back-to-back ninth-inning home runs put them ahead only for the bullpen to blow another late lead.

After its latest defeat, Toronto’s lead atop the AL East at 79-59 is now just 2.5 games on both the New York Yankees (76-61) and Boston Red Sox (77-62).

José Berríos will get the start for the Blue Jays on Tuesday, while the Reds will employ a bullpen day leading with right-hander Scott Barlow after Nick Lodolo, who was originally scheduled to start, was scratched due to illness.

Live coverage on Sportsnet and Sportsnet+ begins with Blue Jays Central at 6 p.m. ET / 3 p.m. PT, followed by first pitch at 6:40 p.m. ET / 3:40 p.m. PT.

Through August and now into September, the Blue Jays’ scuffling bullpen has emerged as the team’s biggest weakness.

On Monday, it was Tommy Nance and Brendon Little who combined to cough up three runs in the bottom of the ninth as top relievers Jeff Hoffman, Seranthony Dominguez and Louis Varland were all unavailable.

Blue Jays relievers last month combined for an MLB-worst 14.2 per cent walk rate with a 4.76 ERA and five blown saves.

Their struggles will put more pressure on Berríos, who hasn’t pitched since Aug. 23 as the team attempted to juggle a six-man rotation. However, manager John Schneider announced Monday that the Blue Jays would be returning to a five-man unit with Eric Lauer headed to the bullpen.

Still, Berríos struggled over the summer, posting ERAs of 5.83 in July and 4.64 in August. But the veteran righty’s last start was among his most solid as he allowed just two earned runs over 6.1 innings against the Miami Marlins while striking out eight.

Meanwhile, Barlow will make his first career start and 68th appearance of the season for the Reds. He holds a 3.26 ERA across 60.2 innings, including a clean two-thirds against Toronto on Monday.

He’ll face a Blue Jays offence that’s been led in recent weeks by Bo Bichette. The star shortstop and impending free agent went 4-for-4 in Monday’s loss, including the go-ahead two-run home run in the ninth and two doubles.

Meanwhile, Isiah Kiner-Falefa is slated for his season debut with the Blue Jays after he was claimed on waivers from the Pittsburgh Pirates over the weekend. Kiner-Falefa will start at third base and bat ninth.

The Blue Jays and Reds wrap their three-game series on Wednesday before the Blue Jays head to New York for a pivotal weekend set against the Yankees beginning Friday.