"For one turn," Roberts said of avoiding a crowded six-man rotation. "You don't ever wish injury upon a player, but things happen."
Ryu suffered the injury sliding into second base in the bottom of the fourth inning of Sunday's 5-3 win over the Phillies. Ryu singled and later slid hard into second when Andrew Toles grounded into a double play. Ryu remained in the game and was able to give the Dodgers 5 1/3 innings to earn his first Major League victory since Aug. 31, 2014.
"He took an aggressive slide into second base and the glute kind of tightened up on him," Roberts said. "So get him in the training room, keep his arm in shape and hopefully he'll make that turn when he's eligible to come off the DL."
Ryu is eligible to be activated from the DL May 11. The Dodgers have a scheduled off-day on Thursday and a full rotation, meaning the club can be cautious with Ryu.
"I think it's probably a start," Roberts said of Ryu's timetable. "He got on base, went there, slide at second base, little tightness in the glute, so I think right now with us, obviously, with the starters and don't want to put him in harm's way at all, so hopefully just a start."
In five starts this season, Ryu is 1-4 with a 4.05 ERA. He missed nearly all of the last two years due to shoulder and elbow surgeries.
The Dodgers recalled right-handed reliever Josh Fields from Triple-A Oklahoma City in a corresponding roster move. Fields is already in his third stint with the Dodgers this year. He's made nine relief appearances, allowing one earned run in seven innings, with 12 strikeouts against one walk. Fields last pitched Friday.
Austin Laymance is a reporter for MLB.com based in Los Angeles. This story was not subject to the approval of Major League Baseball or its clubs.