The weight is on for Red Sox prospect Henry Owens

Henry Owens pitched 168 innings last season in the minors. Barry Chin/Globe Staff

Exposure to a new level typically brings with it some transitional struggles and lessons. That form held for lefthanded pitcher Henry Owens in Triple A Pawtucket at the end of last year.

After a dominant run of nearly two years in High A and Double A in 2013 and 2014, Owens encountered a stretch of some adversity when he landed one level from the big leagues. Though there were stretches of dominance along with 10.4 strikeouts and 2.8 walks per nine innings, the 22-year-old posted a 4.03 ERA in six starts in Pawtucket.

His up-and-down stretch in Pawtucket offered lessons that should benefit the Red Sox’ top pitching prospect going forward. So what were they? Execution of his fastball at the bottom of the strike zone? Greater reliance on his curveball? What was the focus of his offseason?

“I just ate everything in sight,” said Owens, who will make his first Grapefruit League appearance on Friday. “Every day for breakfast I had four or five eggs, depending on how my stomach felt in the morning, three or four pieces of sausage, and two hash browns. I’ll probably be getting a not-so-healthy report back [on a cholesterol test], but I feel healthy, so that’s OK.”

The eating binge, done in concert with a steady offseason workout program meant to tack on muscle mass, was entirely purposeful in an effort to continue a striking transformation now four years in the making.

When the 6-foot-6 Owens was drafted out of Edison High School in Huntington Beach, Calif., in 2011, he resembled a stick figure on the mound. His listed weight of 175 pounds (“On a good day,” Owens chuckled of his weight at the time) represented an aggregation of limbs that seemed in danger of flying apart at any moment.

Now, as he prepares for his fourth full pro season, Owens has filled out considerably. He weighs a solid 220 pounds, having pushed to make strength and weight gains each winter, most notably this past offseason.

Henry Owens in 2011 (left) and this year’s spring training (right).File/Barry Chin/Globe Staff

“The last few starts in Pawtucket I was definitely not feeling up to par,” Owens said. “I feel like the pace of the game didn’t speed up on me [after an August promotion from Double A Portland]. I felt the same. Of course I didn’t execute in some outings. If you look at the stat line, that’s visible, but I think it was physical more than anything. Mentally, I was there, I was ready. Now physically I’m ready, too.”

It came as little surprise that Owens was running on fumes by the end of the year, after he’d dominated in Double A while going 14-4 with a 2.60 ERA and more than a strikeout an inning. By the end of the year, he’d logged 159 regular season innings, another as the starting pitching for the U.S. Team in the All-Star Futures Game, and eight more in the postseason.

His 168 combined innings represented a significant 24 percent bump over his 2013 workload of 135 innings. It was a significant jump, but one that Owens would like to repeat as he aspires to establish himself as a 200-inning pitcher.

“I didn’t really have my legs under me at the end of the year towards the end of the year. My arm felt good but I feel like my body kind of broke down. I was probably 20 pounds less than I am [this spring] of muscle,” said Owens. “When I came into camp, they’re pleased with the mass I put on. I’m just trying to get up to that 200 [inning] range, show them that I’m ready for that.”

Thus far, Owens has been ready to handle the increased responsibilities that the Sox have put on him. His performance of the last two years – in which he’s posted a combined 28-11 record with a 2.82 ERA, 10.4 strikeouts per nine innings, 3.9 walks per nine and a .194 opponents’ batting average – suggests consistent excellence.

Yet within that, there has been change and progress, most notably with a changing physique. The ganglier version of Owens struggled to control his delivery and thus lost the strike zone. But after a season-opening command struggle in 2014, the lefthander worked extensively with Portland pitching coach Bob Kipper, who is now in Pawtucket, to harness his movements in a way that allowed for a breakthrough in his strike-throwing.

After Owens walked 4.8 batters per nine innings in his first nine starts of the year, he issued just 2.7 free passes per nine innings in his last 17 starts. That efficiency allowed him to work deeper into games with more frequency, helping him toward his impressive innings haul.

Henry Owens minor league stats

*-combines Double A and Triple A. Not including postseason.

	W	L	ERA	IP	WHIP
2014*	17	5	2.94	159.0	1.13
Career	40	16	3.34	395.2	1.21

DATA: MiLB.com

Globe Staff

“That was probably the first adjustment to his game last year, getting comfortable in a new body,” said Kipper. “He’s got 6-foot-7 to control. This guy worked tirelessly in Portland to get comfortable with a delivery that was more efficient, more compact, more directional. That’s not an easy task for a guy his size. What we began to see was the improvement in the delivery that allowed him to command his fastball much better. When he started to go on that roll last year, it really started with his fastball, the ability to angle the fastball and pitch predominantly down in the zone.”

There were other markers of progress. Owens began attacking both sides of the plate with his fastball (which registered in most games at 89-94 mph, averaging 91-92) after having worked predominantly to his glove side (in to righties, away from lefties) in the past. He employed his killer changeup (usually viewed as the best in the Sox’ system) more often to lefthanded hitters. His curveball – a third offering that has lagged behind his fastball and change – sharpened and became more consistent, and with the improvement of its shape, Owens showed better feel for when to use it. He made strides in controlling the running game, permitting just 11 steals, down from 19 the previous year.

In short, Owens looked like someone making continued developmental strides. Now, both the pitcher and Kipper recognize the opportunity for more growth as the lefthander tries to position himself to help the big league team at some point in 2015.

If part of the necessary groundwork was at least four eggs a day, so be it. Physically, at least, Owens now looks the part of a big leaguer, someone who is growing into his potential.

“It’s tough to tell the discrepancy from when I first signed till now,” said Owens. “But I think gradually I’ve gotten used to my body, more comfortable in my own skin.”