SCOTTSDALE, Ariz. -- D-backs reliever Yoan López is seeking a change for the better in 2020.

A more consistent slider wouldn’t hurt, either. His fastball is already pretty good, but maybe that was part of the problem last season.

“Velocity has become somewhat irrelevant if that’s what you are featuring, especially out of the bullpen,” general manager Mike Hazen said. “We’ve talked to him about that. We’ve challenged him to really concentrate on the consistency and shape of his secondary pitches, especially his breaking ball, and that’s what we think will help him.”

Last season, López’s fastball averaged 96.2 mph, according to Statcast, and placed him in the 91st percentile in fastball velocity among all relievers. As a result, he was primarily a fastball-slider pitcher and he only threw 30 changeups in his 60 2/3 innings pitched last season.

The slider should be a weapon for him in 2020. The pitch limited hitters to a .195 batting average and .341 slugging. By contrast, opponents sported a .267 batting average and slugged .533 with a slew of extra-base hits against his four seamers.

Overall, López went 2-7 with a 3.41 ERA in 70 games in 2019. He struck out 42, walked 17 and gave up 11 home runs. He went 1-5 with a 5.74 ERA in 26 2/3 innings during the second half of the season. He allowed 17 of the 23 earned runs he gave up all season during that span.

“I’ll focus on the positives from last season,” López said in Spanish. “I had a good start in the first half and the second half gave me a lot of experience that I will need in my career. It’s a long season and a lot can happen, and I learned that. For me, I think the hitters adjusted and I didn’t adjust enough in the full season. I didn’t execute enough. I didn’t locate my pitches enough, but I still feel like I ended it in a good way.”

So far, López is off to a good start. He retired all three batters he faced Sunday against the A’s in his Cactus League debut at Salt River Fields. His fastball was clocked in the upper-90s, and he also tried a few sliders. He’ll get another chance to mix in his secondary pitches when he throws again Thursday against the Reds at home.

“I feel like I’m focused mentally and feeling strong physically,” López said. “The team is giving me the opportunity to win a job and I’ll do everything they will ask of me. I know I can be ready, and it doesn’t matter when or where I pitch in the game.”

López, who has had an eventful ride to the big leagues, says he’s developing off the field too. He’s focused on being professional, being a good teammate and improving his English so he can communicate with all players and staff.

“Being back here in Arizona and speaking English with my teammates helps me a lot,” López said. “I would always use the past tense when I spoke English, but I feel like I am getting better and better at it because of the practice. I’m using the present and future tense more. I know that’s a good sign.”