MIAMI -- Corey Kluber got hit hard again, and the last line drive really hurt.
The struggling Cleveland Indians right-hander broke his right forearm when he was hit by a comebacker during a 4-2 loss to the Miami Marlins on Wednesday night.
Kluber (2-3) was struck by Brian Anderson's liner in the fifth inning.
"It looked ugly," Indians manager Terry Francona said.
Kluber's arm was placed in a cast, and he'll be re-evaluated in Cleveland on Thursday. The Indians will have a better idea at that point of how long he might be out.
"It stinks, you know?" teammate Roberto Perez said. "He's our ace. We're going to miss him."
The two-time American League Cy Young Award winner allowed eight hits and three runs in 4 2/3 innings, which left his ERA at 5.80. The Indians were already without starter Mike Clevinger, who is sidelined until at least June by a back injury.
Caleb Smith (3-0) struck out eight in seven innings to help Miami stop a four-game slide. He allowed one run on Perez's third homer in the third inning.
Even for the victors, Kluber's injury was a downer.
"I'm sorry to see that," Smith said. "He's a great pitcher."
Anderson's infield hit caromed off Kluber, and the ace's arm dangled at his side as he chased down the ball. He swatted it toward first base with his glove rather than throwing it.
"It happened so quick, I couldn't tell where he got hit," said Perez, the Indians' catcher. "I saw him holding his arm. It was tough."
Kluber briefly visited with a trainer and Francona before walking off the field.
"Tito kept asking him, 'How do you feel?' and he was just numb," Perez said. "At that point you start thinking the worst."
The Indians said the fracture was non-displaced, meaning the bone was still properly aligned.
Miami center fielder Rosell Herrera, who came into the game batting .148, had a career-high three RBIs to double his season total. Herrera also made a diving catch to rob Carlos Gonzalez of a hit .
Cleveland's Carlos Santana homered in the ninth off Sergio Romo, who regrouped to earn his fifth save. The Indians, last in the AL in hitting, had just two at-bats with a runner in scoring position.
Smith's unbeaten record is especially impressive because the rest of the Marlins' staff is 6-21. His ERA fell to 2.00, and he has 45 strikeouts and nine walks in 36 innings.
"Every time I looked up, I felt the count was 0-2," the left-hander said. "I'm feeling very confident. I feel I can throw strikes when I want to."
Marlins: RHP José Ureña (1-4, 5.08 ERA) is scheduled to start Friday in the opener of a three-game series against Atlanta. It will be Ureña's first appearance against the Braves since he was suspended for six games for intentionally hitting Ronald Acuña Jr. on the arm with a pitch last August, triggering a melee.
Indians: RHP Shane Bieber (2-1, 3.68 ERA) is scheduled to start Friday when Cleveland opens a homestand against Seattle.
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