Dodgers expect top prospect Walker Buehler to contribute in 2018 — within limits

As Walker Buehler warmed up on Monday morning, preparing to enter the late innings of a minor-league game against the White Sox, an interested observer stood outside the bullpen. Andrew Friedman, the Dodgers president of baseball operations, crossed his arms and watched Buehler prepare to face hitters for the first time since last season. A few minutes later, general manager Farhan Zaidi joined Friedman.

The Dodgers expect crucial contributions in 2018 from Buehler, a first-round draft pick in 2015 and the organization’s top pitching prospect. He tested the waters in the majors last September as a reliever, but the team views him as a possible right-handed weapon to add to its mostly left-handed rotation this season.

Buehler, a 23-year-old right-hander, will not begin the season with the Dodgers. He may not even break camp with a team. The Dodgers will keep a watchful eye on Buehler’s workload this year, with manager Dave Roberts suggesting an ideal output from Buehler would be 140 to 150 innings.

The Dodgers intend to be flexible with Buehler’s usage, and are unlikely to treat those numbers as a hard cap. They act more as guidelines.

“We don’t know how his spring is going to play out,” Roberts said. “We know he’s going to pitch meaningful innings for us at the major league level. We don’t know when. At that point in time, we just have to let things play out themselves.”

Buehler threw 98 innings in 2017. He appeared in three games in 2016 as he returned from Tommy John surgery. The Dodgers do not want to put unnecessary strain on his frame as he rebuilds arm strength.

Buehler faced four batters on Monday. He struck out three and gave up a triple with two outs. He had been tinkering with his slider, looking to reduce the velocity and increase the size of its break. The pitch reached the low 90s in 2017, making it more of a cutter, and Buehler wanted to provide a different look from his fastball.

“The harder you throw it, the less it’s going to break,” Buehler said. “Really, it’s the same pitch. Just trying to throttle it down a little bit and make it a little bit bigger.”

Ryu looking for more spin in 2018

Hyun-Jin Ryu struggled with the command of his curveball during a three-inning outing against the White Sox minor leaguers. He chalked up the lack of command to his experimentation with the shape and speed of the pitch, which he threw 15.6% of the time in 2017.

His average curveball clocked at 71.6 mph, according to FanGraphs. Ryu hoped to increase the velocity and present a more troubling sight for opposing hitters.

“Just thinking of the spin rate, trying to put more spins on it,” Ryu said through his interpreter, Bryan Lee. “I’m not sure how much harder exactly; I can’t put a number to it.”

Ryu could not command the pitch on Monday. Too often, the curveball broke too soon, diving toward the dirt before reaching the plate. Ryu indicated he will keep trying to improve his control of the breaking ball.

“I always knew in theory if you put more spin on it, it would be tougher for the hitters,” Ryu said. “But I never had a chance to try it out during the season. This is spring training. I get to try new stuff and learn things.”

Jansen faces minor league hitters

Rich Hill was sitting at his locker when Kenley Jansen returned to the clubhouse after an inning in the minor-league game.

“How’d it go?” Hill asked.

Jansen sighed.

“Typical spring training.”

Jansen has not hid his disdain for the spring. As a closer, he has trouble replicating the tension of the ninth inning in the placid setting of games in early March. He will only pitch in one or two Cactus League games, with his debut tentatively scheduled for March 9.

The game on Monday presented Jansen an early chance to deal with stress: He permitted a double on the first pitch he threw. After a strikeout and a walk, Jansen ended the inning by inducing a double play.

Jansen pronounced himself ready to face major league hitters later in the week.

“I feel great,” Jansen said. “My body feels great.”

andy.mccullough@latimes.com

Twitter: @McCulloughTimes