SEATTLE -- It was only once Triston McKenzie got to the bullpen about 30 minutes prior to first pitch in the team’s 3-1 loss to the Mariners at T-Mobile Park on Thursday afternoon that the Guardians knew he’d be able to make his start.

McKenzie woke up in Seattle with a stiff neck that was bothersome enough for the club to inform reliever Bryan Shaw to be ready to serve as an opener if McKenzie couldn’t pitch. But after time with the trainers and getting through his pregame routine, McKenzie told his coaching staff he was good to go.

“It was the first time I'd experienced it this year,” McKenzie said. “I literally just woke up and didn't necessarily feel right. Came in and let them know about it, and was able to pitch.”

Maybe that stiffness played a part in his rocky first inning, though McKenzie said that once the game started he didn’t feel any pain or discomfort. However, he found himself in a 26-pitch frame (the third-most pitches he’s thrown in a single inning this season) that started with a walk to Julio Rodríguez. A single followed, before Mitch Haniger launched the third straight slider he saw over the fence for a three-run homer -- the only runs Seattle was able to muster on the day.

“First inning, [he] didn’t look real good,” Guardians manager Terry Francona said. “Wasn’t locating, wasn’t coming out good. Fortunately, kind of got the blood flowing and everything and I thought he pitched pretty well.”

Maybe the neck stiffness didn’t play into the outcome at all. This type of an outing isn’t too far from what we’ve seen from McKenzie all season. Here’s a look at his ERA by inning entering Thursday’s matchup:

First: 4.09
Second: 2.86
Third: 2.45
Fourth: 3.47
Fifth: 3.20
Sixth: 2.79
Seventh: 2.45
Eighth: 4.91 (in just 3 2/3 total innings)

His first inning ERA jumped to 5.09 after Haniger’s three-run blast.

“It's frustrating when you go out there and you give the team six or seven,” McKenzie said, “but I also feel like I was the one that very much contributed to the loss. That's where I was at.”

Last time out, almost the same thing happened. McKenzie gave up two runs against the White Sox in the first before retiring 19 of the next 21 batters he faced. On Thursday, he gave up three runs right away, then proceeded to retire 18 of the next 20 hitters.

"He got us to a point where I think he was a little over 90 [pitches] and I didn’t really want to push it anymore," Francona said. "But you hope that those three runs in the first don’t hold up, but they did.”

It’s no secret that the Guardians need McKenzie at his best in order to continue the potential postseason run upon which they’re trying to embark. Even if he has given up some first-inning runs this year, McKenzie has still been effective, considering his 1.91 ERA since the start of July entering Thursday’s outing was sixth-best in the Majors among qualifying pitchers in that span.

His curveball has arguably been the most difficult to hit of any big league hurler. Coming into this series, opponents had hit just .117 with 59 strikeouts against the offering this season -- the lowest opponents’ average on a curveball in the Majors (minimum of 75 at-bats ending in a curve).

Clearly, what he’s doing is working. But if McKenzie can figure out how to minimize the damage in his early innings, he could become even more elite -- which would immeasurably benefit the Guardians as the home stretch of the regular season quickly approaches.

“He's a good pitcher,” Haniger said. “He's got good stuff. He's got a good riding fastball. He'll throw some really good sliders, and as a hitter, you just want him to miss middle-middle with it and try to put a good swing on it. He's got that big 12-6 curveball too, so I definitely see why he's been good all year."