LAS VEGAS -- Josh VanMeter swung through the pitch and winced. Then the Reds infielder crouched down in the batter's box. That was his introduction to the slow curveball Alec Mills has wielded dating back to last season.

VanMeter chatted with one of Cincinnati's athletic trainers and stayed in the game, but Mills finished off their second-inning battle on Saturday afternoon with a strikeout. In the Cubs’ 8-5 loss to the Reds at Las Vegas Ballpark, Mills flashed the arsenal that has powered a strong spring and has kept the right-hander in contention for the rotation's lone vacancy.

"All I can do is let them make that decision, obviously," said Mills, who allowed one run on four hits with three strikeouts and no walks in 3 2/3 innings against the Reds. "I'm just here to compete. And I think it's been awesome."

The curve, specifically, has helped Mills add another layer to a repertoire that centers around command and keeping batters guessing. His four-seam and two-seam fastballs each clock in around 90 mph on average, and Mills balances that with a changeup (80.7 mph average in 2019, per Statcast) and slider (78.2 mph).

While with Triple-A Iowa last season, Mills began toying around with a curve that would be in a different velocity range than his slider. The righty tested out a grip that included keeping his index finger off the ball (similar to Adam Wainwright's curveball), and he liked the feel of the slower pitch in bullpen sessions.

"Rod [Nichols], the pitching coach in Triple-A, just said, 'Hey, let's see what happens. Throw it in the game,'" Mills said. "I did it a couple times in a game and had some success. And just more and more, I've been able to lean on it."

Last season, Mills' curve clocked in at 67.6 mph on average, according to Statcast. Among pitchers with at least 50 curves thrown in 2019, Mills' pitch had the lowest average velocity. Opposing batters hit at a .143 clip with a .214 slugging percentage and a 33.3 percent whiff rate against the pitch in '19.

As things stand, Mills (out of Minor League options) is a safe bet to have a spot on the Cubs' Opening Day staff, either as the fifth starter or a swing man in the bullpen. He and fellow righty Tyler Chatwood are the leading candidates for the rotation spot. On the spring, Mills has given up just one run in 9 2/3 innings of work.

"What Tyler does, he's disgusting," Mills said. "He's got stuff that can't be hit a lot of times. ... He's getting that job for a reason. He's been doing it for a long time. I'm just going to fight until the end and see what they do, see if they give it to me. If not, I'll try my best."

Leaving Las Vegas
Cubs manager David Ross raved about the year-old Las Vegas Ballpark, home to the Triple-A Las Vegas Aviators. Ross suited up for the team (then known as the 51s) back in 2002. That team won 85 games as an affiliate of the Dodgers, who called Ross up to the big leagues that summer.

"I remember being down the left-field line," Ross said, "and getting the news from my manager that I was going to the big leagues. That was a special moment for me."

Ross debuted for the Dodgers on June 29, 2002, in a 7-0 loss to the Angels. The bench coach for the Angels at the time was Joe Maddon, whom Ross replaced this year as manager of the Cubs.

Worth noting
• In an 8-5 split-squad win over Cleveland at Goodyear Ballpark in Arizona, Cubs right-hander Kyle Hendricks logged four innings. The starter finished with four strikeouts, one walk and two hits allowed, and he yielded one run, via a home run by shortstop Francisco Lindor.

• Cubs third baseman Kris Bryant will be staying in Las Vegas on Tuesday to be with his pregnant wife for a doctor's visit. Bryant will be back with the Cubs on Wednesday and said he might play in three straight games upon his return.

• Following two games off, Cubs first baseman Anthony Rizzo was back in the lineup on Saturday after dealing with a blister on his right middle finger.

• Outfielder Steven Souza Jr. launched a homer off Yu Darvish in a simulated game on Friday at Sloan Park but did not finish his trot around the bases. Ross chuckled when asked if that meant Darvish should not be credited with a run allowed.

"I saw it. It was loud. It was loud," Ross said. "He was like, 'I'm good!' He didn't want that third at-bat against Yu. He wanted to keep that confidence: 'I'm outta here! I feel good today!' I was like, 'You're not going to let Yu get a little revenge on that?'"

Up next
Right-hander Colin Rea will start for the Cubs on Sunday, when a split squad faces the Reds at 3:05 p.m. CT at Las Vegas. Righty Vladimir Gutierrez will start for Cincinnati on MLB.TV and the Marquee Sports Network. Meanwhile, Cubs lefty José Quintana will start opposite D-backs righty Jon Duplantier at 3:05 p.m. CT at Sloan Park in Mesa, Ariz. That game can be heard on Gameday Audio.