Even before Hall of Fame-bound rotation mates Max Scherzer and Justin Verlander were dealt away at the trade deadline, expected No. 3 starter Kodai Senga was the lone member of that trio to be named to the National League All-Star roster this season.

The Japanese import has been particularly dominant over his past 10 starts since the start of July, lowering his ERA to 2.48 over that stretch with a 12-strikeout performance over seven innings in Friday’s 2-1 win over the Mariners at Citi Field.

Suddenly, the MLB rookie ranks third among all qualified starters in the National League overall in that category, with a tidy 3.08 ERA over his first 25 big-league starts.

Senga began the day ranked behind just San Diego’s Blake Snell (2.60) and Chicago’s Justin Steele (2.69), with the lefty former Cy Young winner slated to start for the Padres against the Giants on Saturday night out west.

“I’d be really happy to sign up for next year just like [he pitched] this year,” manager Buck Showalter said of Senga before the Mets’ 8-7 loss to the Mariners. “What happens next year? I just want him to get through this year healthy and we’re on pace to get where we hoped to get [with his workload].”

The 30-year-old Senga (10-7) is up to 143 ¹/₃ innings pitched with probably five starts remaining, which could put him in the 30-start, 175-inning range for the initial season of the five-year, $75 million contract he signed with the Mets as a free agent last December.

Of course, the righty initially was slotted behind Scherzer and Verlander in the Mets’ rotation, but those plans changed once the Mets fell out of playoff contention in July and decided to be sellers at the deadline.

An ERA title certainly would be a significant accomplishment for the rookie hurler, but Showalter understands there is a lot of ground to make up on the NL leaders and “that’s gonna be hard to do … unless he goes crazy for like four or five outings.”

“But I’d like to see him get it under 3.00 I think that would look good,” the manager countered.

Mariners shortstop J.P. Crawford accounted for the Mariners’ lone run Friday night with a fourth-inning homer, but he said afterward that “Senga kept us off balance pretty much” throughout his seven innings.

“Some of the novelty of everything, and being new and everything, that kind of works both ways,” Showalter said. “He’s not the type of guy that [batters think], ‘OK, I’ve seen him, and now I know how to approach him.’ He has a lot of weapons.

“People miss that when he doesn’t have a feel for his split, he’s got other pitches. … The cutter has been a huge pitch for him. He’s also changed the shape of it, and every once in a while, you’ll see it show up on the [score] board as a slider. He’s got a talented hand.”

That talent has translated to Senga being one of the top pitchers statistically in the National League with a month to go this season.