DENVER – If there is anything positive about the Colorado Rockies’ weak start, it might be the left arm and between the ears of 22-year-old rookie left-hander Franklin Morales.

Call it the maturation of Morales.

Morales was instrumental in the Rockies’ late-season run last year. After he was called up from the minors, Morales finished 3-2 with a 3.43 ERA in eight starts. The Rockies would not have made it to the playoffs without him.

Nerves were Morales’ biggest opponent in the playoffs. Face a little adversity and Morales would crumble. Morales has the physical skills to be the Rockies’ ace, but sports are about more than the physical.

He’s a lefty who can throw in the mid 90s. He as a great change-up and can throw a stunning 80 mph curve ball as deftly as he can a 65 mph curve ball.

Morales showed it all in the Rockies 5-2 loss to the Arizona Diamondbacks on Sunday. Morales tossed six shutout innings. He struck out two. He walked three and gave up two hits.

Morales opened the game, baffling the Diamondbacks with three perfect innings. He was aggressive with the all-right-handed lineup, pitching to the Diamondbacks hard and inside. The change up and the curve left several Diamondbacks shaking their heads.

“He was ahead of most of the hitters, I’d say, his entire six innings,” Rockies pitching coach Bob Apodaca said. “I think the only time he wasn’t was in that fourth inning.”

Morales threw 35 pitches in the first three innings, but threw 30 pitches in the fourth inning alone. Still, that’s where we’re seeing growth.

Morales sat down the first 11 batters, then gave up a single Orlando Hudson. Morales threw a ball a to Conor Jackson then let Hudson move to second on a balk. He walked Jackson, then walked Eric Byrnes to load the bases.

Then he started fidgeting. Morales messed with pants and hat several times. He wiped his face, walked to the back of the pitcher’s mound, turned and fidgeted some more. Apodaca walked to the mound and, along with catcher Yorvit Torrealba, had a few words with Morales.

No matter the conversation from pitching coaches or catchers, those are the situations that good pitchers have to learn to get out of if they want to be great.

Morales came in on Justin Upton on the first pitch and made him pop-up for an easy fly ball foul out to first baseman Todd Helton.Disaster averted.

“He knows the areas he needs to improve, rhythm and tempo is one,” Rockies manager Clint Hurdle said. “Dealing with adversity, dealing with traffic on the bases is another. He was able to address those challenges (Sunday) in a real nice fashion.”

Maybe more telling than getting out of that inning was Morales’ actions after getting out of the fifth.

Morales gave up a single and a walk to put runners on base.

With Byrnes batting and two outs, a wild pitch advanced the runners. Morales stayed down in the strike zone. He stayed in, too, forcing a grounder to shortstop Troy Tulowitzki who threw for the third out.

Morales walked off the mound, a fist pump preceding determined and maturing steps.