"I've told everybody," Mattingly said. "He was Clayton. He was Greinke."
Beckett, the 2003 World Series MVP for the Marlins, has been a star and a starter.
Signs of both were there for the second time Sunday when Beckett allowed one hit and struck out three in three scoreless innings, leading the Dodgers to a 5-1 victory over the Cleveland Indians.
Over five innings in two spring starts, Beckett has allowed no runs and two hits. He's struck out six. Before the spring training game at Camelback Ranch, Mattingly dismissed any suggestion that Beckett might wind up in the bullpen.
"I don't think we see Josh in the `pen at all," Mattingly said. "We just don't see that as a possibility."
Then, Beckett showed why he looks as if he would be a good fit in the Dodger rotation behind No. 1 Kershaw and No. 2 Greinke.
Beckett, who was acquired by the Dodgers on Aug. 25 from Boston, got his third of three successive strikeouts in the second against the Indians with a changeup on a 3-2 pitch to Juan Diaz. Throughout spring training, Beckett said, he been working on the pitch and his delivery.
"My changeup has been the key to a lot of my success," Beckett said. "I feel good with it. I'm kind of working on everything. My fast ball is OK. But I could use some improvement there."
Cuban defector Yasiel Puig, who signed a seven-year, $42 million contract with Los Angeles in June, hit a three-run homer in the seventh to give the Dodgers the lead.
Puig hit a full-count pitch from right-hander Fernando Nieve over the left-field wall.
Throughout spring training, the powerfully-built Puig has been creating a buzz. After his homer Sunday, he signed autographs for excited fans.
"The pitchers here are faster and smarter than they are in Cuba," Puig said through an interpreter. "I want to play every day. Whatever happens, happens."
Puig came on for Matt Kemp as a pinch hitter. In a second appearance as the Dodgers designated hitter, Kemp went 0 for 3. Kemp, coming off shoulder surgery, is 0 for 5 this spring.
"Matt's fine," Mattingly said. "Nothing wrong with him. The most import thing right now is just getting up there and taking his swings."
Indians manager Terry Francona liked what he saw in starter Corey Kluber, who gave up four hits in three innings in his third appearance this spring.
"He got his legs under him in first two times out," Francona said. "Today he started to compete."
Shortstop Hanley Ramirez and pitcher Ronald Belisario left Dodger camp for the World Baseball Classic in San Juan, Puerto Rico. Ramirez is on the Dominican Republic's roster. Belisario, is with Venezuela. The Dominican Republic and Venezuela play each other Thursday. .Dodgers right-hander Javy Guerra has been added to Mexico's WBC team. Guerra replaces Arizona reliever David Hernandez. Hernandez joined Team USA, filling a roster spot that opened up when Indian's closer Chris Perez withdrew Friday because of an injury to his left shoulder. .The Dodgers are off Monday. Right-hander Aaron Harang is the only Dodger expected to work. Harang is scheduled for a bullpen session. . The Indians play the Cubs Monday at Mesa's HoHoKam Stadium. Right-hander Carlos Carrasco is Cleveland's scheduled starter. The Cubs plan to go with right-hander Alberto Cabrera.