On Thursday at Dodger Stadium, Ryu, who is recovering from last May's shoulder labrum surgery, pitched to hitters from Single-A Rancho Cucamonga. Roberts said the left-hander threw between 50 and 60 pitches in two up-and-down innings.
"It was a step in the right direction," Roberts said.
Roberts said Ryu will need one more batting practice session before beginning a Minor League rehab assignment.
McCarthy, on schedule with his recovery from last April's Tommy John elbow reconstruction, is "a tick behind" Ryu, Roberts said. He is expected to throw the first of two batting practice sessions possibly next week, then advance to his Minor League rehab assignment.
Roberts said he was hopeful each pitcher would not need the full 30 rehab days in the Minor Leagues before being ready to be activated, and he did allow that the club's rotation status would be a factor in when they returned.
The Dodgers expected Ryu to be ready for the start of Spring Training, but he has had several setbacks. Combining that with back surgery for Brett Anderson, the Dodgers opened the season with a starting rotation that included young right-hander Ross Stripling, who had not previously pitched above Double-A and is two years removed from Tommy John surgery.
Ken Gurnick has covered the Dodgers since 1989, and for MLB.com since 2001.