SURPRISE, Ariz. -- Whether it's to the batter at the plate, or with the food on his plate, Rockies right-hander Antonio Senzatela aims to make better choices.

In his 2018 Cactus League debut Sunday afternoon against the Rangers, in a 4-2 Rockies loss, Senzatela threw two innings, gave up a run on one hit -- Ryan Rua 's opposite-way double off the right-field wall -- struck out two, and walked one.

Most instructive was that he mixed well over the short stint, with 17 fastballs, four curves, three sliders and a changeup. OK, 68 percent is a high fastball percentage, but it was a drop from his 72.5 percent last season in 36 games (20 starts) as a rookie (10-5, 4.68 ERA). A longer stint most likely would have led to more mixing.

• Spring info | Tickets | Schedule

"I can't go fastball all the time," Senzatela said. "This year, when they call the curve, I'll throw the curve. I've got to trust my stuff."

Senzatela, 23, arrived at Spring Training last year with no experience beyond Double-A -- and just 34 2/3 innings there -- and won a rotation spot. He earned April's National League Rookie of the Month Award by going 3-1 with a 2.81 ERA. The following month featured an eight-inning scoreless stint in a win over the Cardinals.

:: Spring Training coverage presented by Camping World ::

However, he soon experienced a drop in velocity that led to a move to the bullpen, plus a brief stint in Triple-A Albuquerque that had as much to do as controlling his innings load as performance.

Off the field, Senzatela was learning to take care of himself over the rigorous Major League season. He noted during August that he had to diversify his diet beyond pizza. Turns out the Rockies were coaching those decisions.

The results are obvious now. After dropping from 245 pounds last year to 227, Senzatela has less upper-body beef. Having grown up in Venezuela with limited options, Senzatela is beginning to make sense of the veritable smorgasbord offered in big league cities.

"We had a sit-down about midway or three-quarters of the way through last season," Rockies director of physical performance Gabe Bauer said. "We made a few changes to his diet and he continued that throughout his offseason. This is definitely where we want him.

"Tyler Hines [the Rockies' culinary nutritionist] played a big part in this, as well, and there was the combination of that and his training regimen that he had in the offseason."

Pitching coach Steve Foster is even more excited about how Senzatela handled his in-game assignment.

"Locate the secondary stuff, which he's doing this spring," Senzatela said. "He's been doing it all spring. He's locating all four -- slider, curveball and change."

On Sunday, Senzatela retired the first two batters before walking Rougned Odor and hanging a slider -- his fourth-best pitch -- against Rua.

"It should have been a home run," Senzatela quipped.

But he was largely effective, and diversity will serve him well.

After all, he won a spot last year not knowing what he ended up learning.

"I needed to trust my abilities to pitch, and go out and compete every time, try and win games for the team," he said. "I need to be more smart with my weight, try not to be too fine with my pitches, and learn the hitters."

Thomas Harding has covered the Rockies since 2000, and for MLB.com since 2002. Follow him on Twitter and like his Facebook page.