GLENDALE , Ariz. -- Six pitches into his first spring start and Cubs debut, Trevor Williams turned to his slider against Dodgers superstar Mookie Betts. Williams has been testing out new grips in Chicago's pitch lab this spring, but he leaned on his trusted version with two strikes.

The pitch took the left turn that Williams wanted, darting low and away into catcher Austin Romine's glove. It was called a strike and Betts smiled wide and had a few words for the home-plate umpire Gabe Morales as he strolled back to L.A.'s dugout. Williams grinned when asked about the effective, yet borderline pitch.

"It was right where we wanted it to go," Williams said. "And he called it a strike. That's a win."

Thursday night's outing to begin the Cubs' 7-0 Cactus League win over the Dodgers was Williams' first chance to bring his recent lab work into a game setting. Chicago signed the right-hander to a one-year contract this offseason, betting on him as a rotation comeback candidate in the hands of the team's pitching infrastructure.

Over two innings, Williams scattered four hits, but he stranded runners on the corners in each of the first and second against the Dodgers. He struck out four batters -- including Betts twice -- and generated seven swinging strikes in a 40-pitch performance.

Last season and the bulk of 2019 were disastrous for Williams, but a right oblique injury two years ago set off a chain of mechanical setbacks. Shortly after signing with the Cubs in early February, Williams sent pitching coach Tommy Hottovy an assortment of side-by-side comparisons from previous seasons, showing he was ready to get to work.

"He was already ahead of what he was trying to accomplish physically," Hottovy said on Thursday afternoon. "He had gone just so far down that path last year, just didn't feel right, was fighting a lot of things mechanically. So he was already ahead of that and trying to work on things.

"It gave me an understanding, one, what he can handle in terms of information, what he was already looking at. So then I was able to just kind of supplement what he was thinking with some other thoughts, ideas, some kind of different ways to approach what he was trying to accomplish."

In his initial Zoom conversation with reporters earlier this spring, Williams said he was eager to get into the lab with Hottovy and the Cubs' team of pitching experts. Together, they have been tackling an assortment of tasks, ranging from delivery to pitch design to pitch selection.

The 28-year-old Williams enjoyed a strong showing in 2018 for the Pirates, posting a 3.11 ERA over 170 2/3 innings. He was off to a solid start in '19 as well, logging a 3.33 ERA through nine outings before the oblique injury flared. Williams returned by June, but he labored to the tune of a 6.58 ERA in his next 17 turns.

And then in the abbreviated 2020 season, Williams went 2-8 with a 6.18 ERA in 11 starts for Pittsburgh. He was designated for assignment over the winter when the Pirates needed room on their 40-man roster for younger players.

"I lost my identity," Williams said earlier in camp. "I lost a sense of what made me good."

The Cubs are working with Williams to find that again.

Mechanically, Hottovy said Williams -- who has a rare combination of a low release point and great extension -- was pulling toward first base on his follow through, impacting his release point. The Cubs have been working with the righty on a more direct line to the plate.

"When he's moving right," Hottovy explained, "and does all the things right up the chain, over the rubber, that front side kind of gets to home plate and then works back to him, versus gets to home plate, gets kind of pulled toward first base. Directionally, he's in a much better place."

In terms of pitch use, Williams' sinker was his No. 2 option in 2018 (18 percent), but it dropped to third in '19 (15 percent) and was an afterthought in '20 (8.4 percent). The slider has climbed to Williams' secondary weapon behind the four-seamer. Hottovy wants to find ways to maximize all of Williams' pitches (sinker, curve and change included) to help set up other offerings.

"We like all the weapons," Hottovy said. "We like guys to be able to use them all. And I think it keeps guys not becoming one-dimensional and not becoming so reliant on execution all the time."

When it comes to pitch design, Williams is currently cycling through slider grips to find one that has a different shape than his usual downward-moving pitch. Hottovy said the goal would be to have a second slider with more "sweeping" movement, giving Williams options for different swing styles.

Williams struck out Betts with his traditional slider, and he got some mixed results with some new ones that remain under construction.

"It's just part of Spring Training," Williams said. "It's part of utilizing the lab. I'm sure we'll go into the lab at some point between now and my next start and fine-tune some more."