At first it was believed that Hyun-Jin Ryu's recent shoulder soreness was normal and that he wouldn't miss much time. Now, Los Angeles Dodgers manager Dave Roberts says that the left-hander won't pitch in spring training and a potential 2016 debut in May is "unrealistic."

The last time Ryu, 28, stepped on a mound during a major league game was on Sept. 12, 2014. He allowed four earned runs on five hits and one walk in one inning of work and then continued to deal with shoulder issues.

Those issues have persisted even after he underwent surgery last year to address the injury. Ryu missed all of last season, and his timetable for a return in 2016 was significantly disrupted with his most recent setback. Add that into the equation with Zack Greinke's departure, Brett Anderson's back surgery, Brandon McCarthy's recovery from Tommy John surgery, Frankie Montas' rib cage surgery, Alex Wood's elbow soreness and Scott Kazmir's rapidly declining velocity, and you have yourself a good old fashioned mess.

As a result, the Dodgers will need their young pitchers to step up if they want to successfully supplement these losses in the rotation. With so many prolonged absences, there is no way that Los Angeles can rely on any of those aforementioned names to efficiently contribute for the duration of 2016.

Here are three prospects that the Dodgers will need to make an impact at some point.

Julio Urias

Over the weekend, Roberts didn't rule out the possibility of Urias grabbing a spot on the Opening Day roster.

 "If he's throwing well enough and we feel good enough for him to be in that spot, it's realistic," he said.

The left-hander is still only 19 years old, but he dominated Double-A Tulsa last season (2.77 ERA in 13 starts) and impressed in his first inning in spring training this month by striking out the side. He gave up three runs the following inning, but the coaching staff was impressed with the way the ball was coming out of his hand.

At this point, the only glaring issues with the lefty were his final two outings at Triple-A Oklahoma City last season and that second inning last week against the Los Angeles Angels. However, if he continues to impress this spring and the team is in need of a starter, Urias could make his MLB debut much sooner than expected.

Jose De Leon

The right-hander, who is a former 24th-round pick and wasn't expected to be a top prospect, has rocketed his way up the Dodgers' system. He led the minor leagues with 12.8 strikeouts per nine innings in 2015 and maintained a 2.99 ERA in 23 starts between High Class A Rancho Cucamonga and Double-A Tulsa.

He's made three relief appearances this spring, but two of them haven't gone very well. He's allowed five earned runs on nine hits, including three home runs, but managed to strike out four batters and allow just two hits in a two-inning appearance. It's clear that De Leon needs some more time to develop, but he's been sensational in his past two minor league seasons and is regarded as one of the top pitching prospects in baseball.

If he can settle down and be consistent for the rest of the spring and then get off to a quick start in the minors, he could be a candidate to get some starts in the big league rotation.

Zach Lee

The 24-year-old made his MLB debut last season and was shelled in his only outing. He allowed seven earned runs on 11 hits and a walk over 4-2/3 innings against the New York Mets, but he's got potential to be a mid-rotation starter that eats up innings (he threw 142-2/3 innings in 2014 and 150-1/3 in 2014).

This spring, he's allowed three earned runs on four hits and a walk in two starts. While that doesn't sound too great, his opponents' batting average is just .222, and one of those starts featured a hitless two-inning outing.

The right-hander registered an impressive 2015 campaign at Triple-A Oklahoma City. He went 11-6 with a 2.70 ERA, 1.11 WHIP and 81 strikeouts in 19 starts (113-1/3 innings). He's proven almost all he can at that level, so if he can make a case during the rest of spring training, he, too, can be a candidate to get a start or two with the Dodgers in April.

*Note: Brandon Beachy and Mike Bolsinger are others who are also likely to see starts as the Dodgers cope with numerous injuries.