PITTSBURGH -- Six years ago, 24-year old Tyler Glasnow was a raw, but highly promising, right-handed talent for the Pirates, just trying to find his footing as a big league pitcher.

As he struggled with command for parts of three seasons in the organization, Glasnow was demoted to Triple-A Indianapolis on several occasions, before ultimately settling into a full-time role in the Pirates’ bullpen during the start of the 2018 season. That was before the front office traded him to Tampa Bay as part of a package for right-hander Chris Archer.

Now one of the National League’s most formidable arms, the former No. 9 overall prospect finally got the opportunity to face off against the team that drafted him Tuesday night in Pittsburgh. Glasnow made the most of his return by striking out nine batters during his six innings of work in Los Angeles’ 1-0 loss in the series opener at PNC Park.

“It was cool,” Glasnow said. “A familiar feeling. I hadn't been back in a while.”

Glasnow threw 97 pitches, 61 for strikes, and walked just two hitters. Despite being issued the loss, Glasnow lowered his ERA to 2.93 and his WHIP to 0.90, the third-lowest mark among qualified MLB pitchers. The righty was able to limit the production of Pittsburgh’s top bats, and kept the ball on the ground for the majority of his outing, recording eight ground-ball outs.

With his fifth punchout of the game in the fifth inning, Glasnow became the first pitcher this season to reach the 100-strikeout threshold. He is the first Dodger to be the first pitcher to reach that mark in a season since Clayton Kershaw in 2016.

Glasnow incorporated his four-seam fastball, slider and curveball well, making Pirates hitters whiff on 33 percent of their swings.

“From Tyler, I thought he threw the ball great,” Dodgers manager Dave Roberts said. … His pitch mix was great and he went deep again.”

The sole blemish on Glasnow’s outing came with one out in the third inning when Pirates center fielder Jack Suwinski, batting with a full count, drilled a 97 mph fastball at the top of the strike zone a Statcast-projected 375 feet into the right-field seats.

It was by no means a tape-measure blast, but the solo home run provided enough offense to defeat Los Angeles.

“[Glasnow] made a good pitch on Suwinski, [but] he was hunting the heater and put a good swing on it,” said Roberts.

Glasnow’s only other jam came in the sixth inning when the Pirates put runners at second and third with two outs. However, Glasnow was able to work out of it, striking out left fielder Nick Gonzales looking with a fastball painted on the inside of the plate.

It was moments like that in a close game that a younger version of himself may not have navigated as well. Even Glasnow himself was candid about the improvements he’s made since being dealt to Tampa Bay.

“Then, I just sucked every time,” he said. “Now, I feel like I’m better than I was then. So, definitely a stark difference, for sure.”

Roberts recalled first hearing around Glasnow during his first few seasons as manager of the Dodgers. He mentioned the youthful trio of Glasnow, Gerrit Cole and Charlie Morton. But since becoming his manager, Roberts has learned a tremendous amount about the right-hander that goes far beyond his dominance on the mound.

“As I’ve gotten to spend more time with Tyler, [I’ve found that] he’s very worldly,” Roberts said. “I think he’s very well-rounded, very intellectual, obviously a very good competitor. I do remember the young Tyler Glasnow, Pittsburgh, big arm.”

Pirates designated hitter Andrew McCutchen, the lone former Bucco teammate of Glasnow’s that is still with the organization, remembers the highs and lows that the pitcher experienced during his early days in the league.

“He had no idea where the ball was going when he would come up to the big leagues,” the 11-year Pirate said. “It would be a little erratic and then he would figure it out for an inning and then he would be erratic again. He couldn’t figure it out. He couldn’t put it all together when he was here. I knew if he did figure it out, he would be pretty good.

“It’s not a surprise he’s done what he’s done. It makes sense now. I just wish he could have done it when he was here.”