The Dodgers are hopeful that Clayton Kershaw, scratched from his start in Game 2 of the National League Championship Series with back spasms, will be able to go in Game 4 on Thursday, but the injury has nonetheless scrambled their pitching strategy and tested the depth on which the organization prides itself.

Rookie Tony Gonsolin, who would have been the most likely Game 3 starter, took Kershaw’s spot for Game 2. With therapy and medication, Kershaw had recovered enough to play catch on Tuesday and did his typical bullpen work without actually throwing (called dry work).

Manager Dave Roberts said the likelihood of Kershaw starting in the series “is very good,” but Julio Urías will start Game 3 on Wednesday, as Roberts ruled out Dustin May after he pitched 1 2/3 innings in relief of Walker Buehler in Game 1 on Monday.

Roberts said Kershaw felt the back spasm after throwing a bullpen session on Saturday. Management, which had announced that Gonsolin would throw a simulated game on Saturday, quietly scrapped that and prepared him for the Game 2 start. Kershaw was seen walking into Globe Life Field in Arlington on Monday with a portable electronic stimulator hooked up to his lower back.

“We tried to kick the can down the road as long as we could, and today he just woke up and felt it wouldn’t be smart,” Roberts said. “Each day Clayton got a little bit better and our goal was to have him start tonight, but it never got to the point we got comfortable.”

Kershaw’s renaissance this season has been credited to an uptick in velocity. But in his most recent start, in Game 2 of the NL Division Series, his fastball velocity dropped from a first-inning average of 92.5 mph to 90.6 mph in his final inning. The second of back-to-back home runs that inning hit by Eric Hosmer came on an 89.7 mph pitch. Hosmer saw first-inning fastballs of 92.8 and 92.4 mph. The speed of Kershaw’s slider slowed by nearly 2.5 mph from the second inning to the 86.8 mph one Manny Machado homered on in the sixth inning.

Kershaw opened this season on the injured list with back spasms and missed the minimum 10 days. He had been lined up to start Games 2 and 7.

Already trailing the Braves 1-0 in the NLCS, the Dodgers will now start Gonsolin, who will be making the first postseason appearance of his career. Because Los Angeles swept the previous two series, the 26-year-old right-hander has not pitched in 17 days, with his last regular-season start coming against the Angels (6 IP, 4 ER) on Sept. 26. Roberts said Gonsolin threw a four-inning simulated game “about a week ago.”

Gonsolin, made nine appearances (eight starts) in the regular season and compiled a 2.31 ERA with 46 strikeouts against just seven walks and two homers allowed in 46 2/3 innings.

Back injuries have haunted Kershaw since 2016, when he was diagnosed with a herniated disc and missed more than two months of the season. In 2017, he missed five weeks with a lower back strain, three weeks with a strain in '18 and had to be scratched from Opening Day this year, missing 10 days with another mild back strain.

Roberts said the current injury is unrelated to the Opening Day injury, although once a pitcher has any back injury, they usually require constant maintenance and frequently result in setbacks.

Despite that setback, Kershaw was enjoying a resurgent 2020, finishing the regular season with a 2.16 ERA across 10 starts before combining 19 strikeouts with just one walk while winning each of his first two postseason starts.