LOS ANGELES -- Dodgers pitching prospect Jose De Leon was finally back the mound on Tuesday night, starting for Triple-A Oklahoma City at Round Rock. He threw three perfect innings in his first game in five weeks.

The right-hander retired all nine batters he faced against the Rangers' affiliate, striking out six, including five strikeouts in a row at one point. He threw 37 pitches. The Round Rock lineup featured seven batters with major league experience, including Joey Gallo, Justin Ruggiano and Ike Davis batting 4-5-6. That trio all struck out against De Leon.

De Leon last pitched five weeks ago, striking out nine in five scoreless innings on May 3. But he missed the last five weeks since then with shoulder soreness, and on Tuesday night is expected to throw just three innings in his first time back, approximately 40 pitches.

That May 3 start came after staying behind in extended spring training to bulk up for the season. It has been a trying season for De Leon, who entered the season as the Dodgers' second-best pitching prospect. He showed up on national rankings as well, ranked the No. 23 prospect in baseball by Baseball America, 24th by MLB.com, 28th by Baseball Prospectus, and 60th by ESPN.

The 23-year-old right-hander is coming off a season that saw him post a 2.99 ERA in 23 starts between Class-A Rancho Cucamonga and Double-A Tulsa, leading all Dodgers minor leaguers with 163 strikeouts in his 114⅓ innings.

De Leon last pitched on Friday in an extended spring training game in Surprise, Ariz., along with Ross Stripling.

To make room for De Leon on the roster, Oklahoma City placed converted outfielder turned pitcher Jordan Schafer on the disabled list. The 29-year-old in his first season on the mound has 26 strikeouts and five walks in 24⅓ innings, but has allowed seven runs on 14 hits in 5⅓ innings with Triple-A after allowing seven runs on 15 hits in 19 innings in Double-A.