The Dodgers are hoping Hyun-Jin Ryu can regain his form from April. Sean M. Haffey/Getty Images

The Los Angeles Dodgers didn't acquire a starting pitcher at the trade deadline but have two left-handers that should return by season's end. Hyun-Jin Ryu and Julio Urias were expected to feature prominently in the second half of the 2018 season but the Dodgers may have to wait until September for them to return to the active roster.

Ryu last pitched on May 2 after suffering a serious groin injury. In his first minor league rehab assignment Thursday, Ryu pitched four scoreless innings for Class-A Rancho Cucamonga. He threw 47 pitches, striking out four and allowing just two singles.

The 31-year-old had looked promising in five starts in April. In 29.2 innings this season, Ryu has a 2.12 ERA and a 0.88 WHIP. Should Ryu regain his form, manager Dave Roberts may give him a strong look as a postseason starter after Ryu sat out the 2017 postseason.

The fate of Urias is less clear. Considered one of the best young pitchers in baseball at the start of the 2016 season, Urias has been sidelined since June 2017 with a left shoulder injury and after undergoing season-ending anterior capsule surgery. The original timetable was for Urias to return in 12 to 14 months.

"We feel pretty confident that he will pitch for us next year," president of baseball operations Andrew Friedman said in June 2017. "This is baseball and things like this happen. Obviously, it's personal to us. We know how hard Julio worked this offseason. He had high expectations of helping us win, as did we."

On Monday, Urias pitched 1.2 innings in his first rehab assignment for the Dodgers' Arizona League club. He didn't allow a run and his fastball reportedly reached 94 miles per hour.

Should Urias not suffer any setbacks, it is reasonable that the 21-year-old could serve as a reliever.

The Dodgers currently have six starters but no clear No. 2 behind ace Clayton Kershaw. The rest of the Dodger rotation consists of Alex Wood, Rich Hill, Ross Stripling, Walker Buehler and Kenta Maeda.

Los Angeles has the No. 2 pitching staff in baseball with a 3.45 ERA.