Another lefty, Hyun-Jin Ryu, will start Monday against the Rockies at Dodger Stadium.
"As an organization, we have to do what we feel is best," Roberts said of choosing Stripling over Wood. "This is a tough decision, but we just feel right now, with the five guys we're going to run out there every fifth day, it gives us the best chance to win."
Stripling joins Walker Buehler, the Dodgers' Friday starter, to give Los Angeles two right-handers in the rotation.
"It is good," Roberts said. "Ross actually gets lefties out a little bit better, but he is a guy who throws from the right side and is a different look."
Roberts said Wood, coming off a poor outing Monday in Cincinnati, where he allowed seven runs (six earned) in 3 2/3 innings, will appear in relief "for the foreseeable future unless something changes."
"Two reasons," Roberts said of Wood's role change. "No. 1 is he's done it before and he's really flourished in that role. And we expect him to pitch leverage innings and dominate. That's probably the main reason."
Wood (8-7, 3.65 ERA) has pitched in relief 37 times in his career, going 4-2 with a 2.53 ERA. He has 129 career starts in his six-year career with the Braves and Dodgers.
Wood last pitched in relief on April 15, 2017, with the Dodgers.
Roberts said Wood received the news well and that Wood would pitch "an inning or two at a time."
"Obviously, he sees himself as a starter. We do as well," Roberts said. "But right now, where we're at with the roster, there's got to be some concessions made by a lot of people. He received it like a professional and said he'll do whatever we expect. I knew he would say that. He's going to help us pitch some big innings."
Wood was one of the Dodgers' best pitchers last season, when he was 16-3 with a 2.72 ERA in 25 starts and two relief appearances. He finished ninth in the National League Cy Young Award balloting.
David Wilhelm is a contributor to MLB.com based in St. Louis.