PORTLAND — Perhaps Henry Owens had an inkling of what was to come when he was asked about the pressure that comes with rapidly advancing through the Boston Red Sox farm system as a highly-touted prospect.

“I think it’s just building upon more expectation, and until those expectations are met, I’m still a 21-year-old kid from Huntington Beach, Calif., playing in the Red Sox organization,” he said.

Two days later, on Opening Day, Owens tossed a rain-shortened, six-inning no-hitter, the first since the Sea Dogs became a Boston Red Sox in 2003. 

Talk about building expectations.

Owens has done nothing but enhance his resume since arriving in Portland on Aug. 1, 2013. In seven Double-A starts going into Wednesday’s start against Trenton, he was 4-1 with a 1.49 ERA and three-times as many strikeouts (55) as hits allowed (18) in 36 1/3 innings.

Those numbers improved Wednesday with another scoreless outing against the Thunder in which he struck out nine, didn’t walk a batter and allowed six hits in 6 2/3 innings in Portland’s 9-2 victory.

The 6-foot-6, 205-pound lefthander out of Edison High School was Boston’s 2011 compensatory first-round draft pick, which they received for losing Victor Martinez in free agency. He did not pitch professionally until the Fall Instructional League in Florida. He worked on commanding his fastball at Single-A Greenville in 2012, then dominated at High-A Salem for current Sea Dogs manager Billy McMillon in 2013 before getting promoted to Portland.

“He was a very, very good pitcher for us,” McMillon said. “He kept us in ballgames. He struck out a lot of batters (123 in 104 2/3 innings). He went about his business the right way and hopefully, true to form, he’ll be like that again this year.”

Owens felt comfortable right away at Portland and didn’t miss a beat. In 26 starts between Salem and Portland, Owens led all qualifying minor leaguers by holding opposing batters to a .177 batting average.

Owens attributed the breakout in his second season to learning more advanced training methods, especially in the weight room, where he said he was more adept at building beach muscles than pitching muscles.

“Seeing guys in the weight room really attacking their legs and core, and I’d be doing bicep curls and tricep push downs was a wake-up call,” Owens said. “Just seeing guys out of college that has a lifting program, and they were doing it on a five-to-six-day-a-week basis, really shaped how I changed my lifting regimen.”

The extra muscle and weight on his frame not only improved his endurance but also increased his velocity.

The Red Sox wouldn’t mind seeing that trend continue for their top-ranked pitching prospect. While Owens has put up impressive strikeout numbers, he doesn’t have a blazing fastball. It usually tops out at 93 mph. His sharp 12-to-6 curve and plus change-up and confidence in those pitches keeps hitters guessing.

“He throws several pitches for strikes and he’s not afraid to use them at any time,” McMillon said. “His maturity, his ability to locate, all of that stuff makes him as good as advertised.”

The Red Sox wanted to see for themselves if that was indeed the case and invited him to spend part of spring training. He threw 4 1/3 innings for the big club, but Owens wasn’t looking to impress John Farrell as much as observe how the World Series champions work.

“It was great throwing against big league hitters, but I think the big thing was just watching and listening,” he said. “The most beneficial part was seeing how they take each day and how they get after their craft.”

If anything, Owens was building his own expectations for what his career might be like in a year or two. So what did he learn?

“Make sure that everything I do is with a purpose whether it’s playing catch, whether it’s lifting, whether it’s doing my side work,” he said. “You could tell, once they get on the field, they don’t take any time off. It’s all business.”

Owens is back to doing his business in Portland, but expect a limited engagement.