Kluber pitched well enough to get the win in Cleveland's 4-3 loss to Baltimore on Friday night, but was once again plagued by a lack of run support.
"Corey has done a great job for us all year," Indians reliever Marc Rzepczynski said. "You want to win those games when your ace goes out there. We're not doing a great job of doing that."
Kluber, the reigning American League Cy Young Award winner, has a 3-9 record despite a 3.66 ERA in 2015. The right-hander has gone at least seven innings in four of his last five outings, but has an 0-4 record and 3.97 ERA to show for it.
However, over those five outings, Kluber has received only five runs of support over 34 innings, and two of them came on Friday.
Even with his ace getting three or fewer runs of support in 15 of his 16 outings this season, Indians manager Terry Francona isn't concerned about Kluber's psyche heading forward.
"I care about him a lot, but he's a tough kid," Francona said. "He will show up tomorrow and work his rear end off just like he always does. Every time he pitches, we feel good. Just have to fight through it. Our guys are fighting, too. Sometimes that's the way this game is."
Kluber was sharp again on Friday, going seven innings and allowing seven hits, three runs and one walk while striking out 10. It was the fifth time this season that the right-hander struck out at least 10 batters and the 18th time in his career.
He gave up a solo home run to J.J. Hardy in the second inning, and didn't run into trouble again until the sixth when he gave up hits to Jimmy Paredes, Chris Parmelee, Ryan Flaherty and a sacrifice fly to Hardy.
"The first hit, I left a changeup up a little bit," Kluber said. "He was out in front, but he was able to dump it in there. Get to a full count against Parmelee, and I made a pretty pitch, but it's a full count so he's looking for a fastball and he did a good job of hitting it. I had Hardy set up pretty well, and I just didn't throw a very good pitch and he was able to get the sacrifice fly."
Kluber was able to rebound in the seventh with a 1-2-3 inning, but that will be overshadowed by Rzepczynski's eighth. The lefty trotted out to the bullpen to begin the inning, and three pitches later walked with his head down to the Cleveland dugout.
He threw just three pitches, and each went for a hit. The second pitch resulted in a single down the right-field line by Chris Davis which gave Baltimore its go-ahead run.
"Today, every pitch I threw, literally, they got a hit on," Rzepczynski said.