OAKLAND -- When the Blue Jays first took on the A's in 2022, they were both hovering around the .500 mark and finding their way early in the season. Since then, the teams have diverged significantly: Toronto is in the mix for the American League Wild Card race, while Oakland sports the worst record in the Majors.

After a tough 4-4 homestand against division rivals, a three-game series against the lowly A's seemed like just opportunity the Blue Jays needed to pick up a bit of steam.

Instead, the Blue Jays couldn't get much going Monday night against A's left-hander Cole Irvin, falling quietly to Oakland, 5-1, in the series opener. Toronto has now lost four straight games for just the second time this season.

It may have been more surprising to see Alek Manoah, Toronto's most consistent starter and a dark horse Cy Young contender, get touched up for a season-high five runs (four earned) and take the loss. He was able to grind through 5 2/3 innings and limit reliever usage after a taxing series for the bullpen, but he lacked the sharpness that has defined his 2022 season.

"He just didn't have it today," manager Charlie Montoyo said. "He battled, but again, he didn't have his best fastball today."

The Blue Jays, who entered the series with a league-best .762 OPS, couldn't muster up much in support of Manoah, scattering five hits against Oakland pitchers. By contrast, the A's, whose .199/.267/.298 home slash line is the worst in the Majors, were able to capitalize on Manoah's off night.

Oakland broke the game open early by putting up a three-spot in the first inning. Manoah was hit harder than usual; A's batters averaged a 90 mph exit velocity on his pitches, higher than his career average of 86.8 mph.

“I think he wasn’t throwing as hard as he was before," said Oakland's Ramón Laureano, who took Manoah deep on Monday. "If he’s throwing slower, that makes the slider and the game plan a little more easier for us. But he still had great pitches, and he did the most that he can.”

There was certainly something to that: Manoah's velocity was down a tick on Monday. His pitches averaged around 2 mph slower in the beginning of his outing, but he started to throw harder as the night went on.

Manoah maxed out at 94.1 mph on his four-seamer, right around his season average for the pitch. Overall, though, his average four-seam velocity was just 92.4 mph, about 1.5 under that season average.

"There was nothing wrong," Montoyo said. "We did ask, because any time you don't see someone's best fastball, you always ask. It was fine, he was fine, his arm was fine."

Said Manoah about the velocity dip: "I absolutely have no clue."

The big righty did seem to regain his form in the middle of his outing, striking out three and allowing just two baserunners from the second through the fourth innings. But the opportunities that he and the team missed clearly left a sour taste in his mouth, as he reflected on his night in words that were short and to the point.

"I just tried to come out today and give the team a spark," Manoah said, "and I wasn't able to do that."

It wasn't his best night, but it didn't make a significant dent in what has been an eye-opening sophomore season for Manoah. The four earned runs added to his tally raised his ERA to 2.33, which is still the third-best mark in the American League among qualified starters. He is also tied for ninth with Seattle's Robbie Ray in opponents' batting average at .213, which only increased a tick from his .209 mark entering Monday's series opener.

As long as Manoah is feeling physically good, one bad start is not necessarily a reason to sound the alarm bells -- especially with his track record in 2022.

What's important is that Manoah moves forward from Monday's tough time. He expressed as much after the game.

"Just throw it in the trash can, forget about it and keep going," Manoah said.