CLEVELAND -- The Mariners turned to Felix Hernandez to salvage their road trip and keep the team's already slim playoff hopes alive.

But Hernandez, who has been the team's stopper all season long, was unable to overcome a Jose Lopez error as the Mariners lost, 6-1, to the Indians on Sunday at Progressive Field.

Seattle came into the series finale hoping to win the series and split its six-game road trip. But thanks to a costly error that led to four runs in the sixth, not even Hernandez, who has pitched his best on the road, was able to salvage the trip.

"Every time he goes out there, it seems like he has to carry the burden of stopping a losing streak," manager Don Wakamatsu said. "I thought his stuff was fine, I thought he was in good shape until the ground ball at second base [in the sixth]. When those individual errors happen, at that point, it's hard to come back."

The 23-year-old Hernandez has been Cy Young Award-caliber all season.

He's in the top 10 in virtually every essential category and has the type of dynamic stuff it takes to win the award. But if Hernandez wants to be considered, his team will have to start taking his good outings and making wins.

After a loss Sunday, Hernandez is now winless in his past four starts.

"He's had a great year and he's done a lot for this ballclub," Wakamatsu said. "I think there is a lot riding on that right now. He's having a lot emotionally going on with his year right now."

Hernandez didn't appear to be up to his usual standards from the beginning as Grady Sizemore tripled and later scored on a single by Jhonny Peralta to give the Indians the early lead.

But outside of a Peralta homer in the fourth, Hernandez settled down and locked himself into a pitchers' duel with Indians starter Fausto Carmona.

That all changed in the sixth, however.

With one out in the inning, Peralta (who else?) reached first when Lopez let a ground ball get past him for an error. With Hernandez finding his groove and the bottom of the order coming up, the error seemed harmless.

But just like Michael Saunders' error in Saturday's loss, the mistake proved costly.

Travis Hafner and Saturday's hero, Luis Valbuena, connected on back-to-back singles to score Peralta and give the Indians a 3-1 lead. Two hits and a sacrifice fly later, Hernandez was finished and the Mariners were staring up at a 6-1 score.

Hernandez pitched six innings in all, giving up six runs (three earned) on nine hits with six strikeouts and no walks.

"You have a letdown like that and it takes a little bit to get refocused," Wakamatsu said. "You just don't see Felix give up three hits and a sacrifice fly like that in a row."

Peralta had another take.

"I don't really hit him good," Peralta said. "Today was a different day. He was starting really good, and in the sixth inning, I think he got a little tired."

Hernandez (12-5, 2.73 ERA) didn't make any excuses afterward, either. He said he wasn't even thinking about the error.

"I had no luck today," Hernandez said. "I made good pitches, they just hit the ball good."

It didn't help Hernandez that his teammates couldn't give him any support. While Carmona has been much better of late, he's still struggled to find his command throughout the year. But the Mariners only coaxed one walk out of Carmona, and outside of Ken Griffey Jr.'s 624th career home run in the fourth, the Mariners were unable to do much of anything offensively for the second consecutive game.

Seattle has now lost four of six on the road swing. It fell under .500 on the road and must now regroup quickly against Oakland.

"We can't afford to make critical mistakes," Wakamatsu said. "That's the bottom line."