PHOENIX -- Another day, another big league debut. They’ve become frequent for the Padres over the past two seasons.

This time, it was 23-year-old right-hander Ronald Bolanos, San Diego’s No. 15 prospect per MLB Pipeline. He became the 16th Padres player to make his Major League debut this season, which leads the National League and is tied for second in MLB with the Rangers, behind only the Mariners (17). San Diego’s 32 MLB debuts since the start of 2018 lead the Majors.

• Box score

While Bolanos got off to a tough start, he settled in to deliver six solid innings in the Padres’ 2-1 loss to the D-backs at Chase Field on Tuesday night. The righty gave up a pair of runs on five hits and two walks while striking out four.

“I was a little bit anxious at first, but I think that’s normal for a lot of debuts,” Bolanos said through an interpreter.

That may have contributed to Bolanos’ challenging first inning. The right-hander’s big league career started with a leadoff triple to Ketel Marte, followed by an RBI single to Josh Rojas. And three batters later, Rojas scored on Jake Lamb’s fielder’s choice.

After that, Bolanos didn’t allow another run while working out of several jams. He gave up leadoff hits in the third, fourth and fifth -- which included doubles by Adam Jones and Marte -- yet he retired the subsequent three batters in each of those innings.

“As the game wore on, you saw the tempo slow a little bit, the game slowed down,” Padres manager Andy Green said. “He started to throw some really good curveballs late in the game. I think he struggled to find his spin early, probably a little jacked up, fired up, ready to go. … To watch a young kid settle in and start to punch a few guys out and execute pitches under stress, it was a really good first outing in the big leagues for him.”

Before the game, Green raved about the velocity range that Bolanos shows with his four-seam fastball, and that was on display during his outing. His four-seamer dropped as low as 91.2 mph and maxed out at 98.6 as he threw 60 heaters, which averaged 95 mph, among his 88 pitches.

“He’s throwing 99 in the fifth and sixth inning when he has to reach back for it,” Green said. “That’s rare to see a starter at that velo range. It’s rare to see, even more so, a starter have that velo range with the depth on the breaking ball he had as the game wore on.”

Signed by the Padres out of Cuba during the 2016-17 international signing period, Bolanos doesn’t have much experience in the higher levels of the Minors. He started the year with Class A Advanced Lake Elsinore before pitching in 15 games (13 starts) for Double-A Amarillo, where he went 8-5 with a 4.23 ERA.

San Diego’s lineup couldn’t help Bolanos get his first big league win. Arizona right-hander Merrill Kelly tossed seven scoreless innings, allowing only three hits. The Padres didn’t score until Wil Myers’ two-out RBI single in the ninth, then left the bases loaded to end the game when Nick Martini struck out looking against D-backs right-hander Archie Bradley.

However, Bolanos should have more chances to notch a victory during the final month of the season as San Diego continues to evaluate its young players.

“All the ingredients are there. Time is what’s necessary right now,” Green said. “The composure was really solid for his first game in the big leagues.”

For Bolanos, he has a quality outing to build off as he looks to make an impression during his first stint in the big leagues. And with the top-notch fastball he utilizes, it should help him produce more positive results.

“I felt good. I felt confident out there and I feel like I had some good success, and hopefully I can continue to do that,” Bolanos said. “I think it gave me more confidence. I think it also gave me more confidence to throw my fastball, because I was able to throw it tonight to get out of [tough] situations and get some outs.”