LOS ANGELES — The Dodgers optioned left-hander Julio Urias to Class-A Rancho Cucamonga on Friday, but plan to call him up once active roster limits expand in September.

This was more of a procedural move, since the minor league rehab assignment for Urias reaches 30 days — the maximum amount allowed per the collective bargaining agreement — on Tuesday, four days before active rosters can include 40 instead of 25 players. Urias will have to stay down in the minors for 10 days, unless replacing an injured player, which means the earliest he could join the Dodgers is Sept. 3.

Urias has 15 strikeouts and two walks in 8⅔ innings in five minor league rehab starts between Arizona and Class-A Rancho Cucamonga, but has also allowed three home runs and sports a 5.19 ERA. He last pitched Tuesday for the Quakes, striking out five in 2⅓ innings, with a solo home run his only hit surrendered.

“From my understanding, he felt good coming out of it,” manager Dave Roberts said.

The Dodgers’ plan for Urias, who had left anterior capsule surgery on his shoulder in June 2017, is to pitch in relief, though given his history as a starter it seems highly unlikely he would be used on back-to-back days, something Urias has never done.

He will pitch next for Rancho Cucamonga on Monday on the road in San Bernardino.

“We have to make a decision on how we’re going to use him,” Roberts said. “Obviously it’s going to start with lower leverage, potentially into higher leverage situations.”

Urias, who debuted in 2016, will still be the youngest player on the Dodgers in 2018, having just turned 22 on Aug. 12.

Urias was on the 60-day DL so before he was optioned he had to be added to the 40-man roster. To make room, Josh Fields was transferred to the 60-day DL. He’ll be back relatively soon too, as he is currently on a rehab assignment of his own, with three scoreless innings since joining Triple-A Oklahoma City.

“Josh won’t be before September 1,” Roberts said. “We’re hoping for a back-to-back outing in a few days. He’s progressing slowly.”

Fields last pitched in the majors on June 26, out with right shoulder inflammation, so this move did nothing to alter his timetable.