CLEVELAND -- On Derby Day, the Mariners brought back the dinger derby that had compelled the hottest start in baseball. But not even that was enough to overcome the continued relief and defensive issues that have contributed to Seattle’s swift fall from grace.

The Mariners hit four solo home runs off Indians starter Carlos Carrasco on Saturday, but the two-run shot from Carlos Santana -- who was a Mariner for all of 10 days in the offseason -- hit off reliever Connor Sadzeck in the bottom of the eighth was the homer that mattered most in Seattle’s 5-4 loss at Progressive Field. It was the Mariners’ sixth straight loss and 15th in their last 20 games.

“It’s good to see guys hit homers and run into homers,” said Tim Beckham, whose solo shot in the top of the eighth had briefly given the Mariners the lead. “But we want to win.”

They’re not winning lately for a number of reasons. Before this homer spree, the bats had cooled considerably from the scorching start. The Mariners hit 51 homers in their first 23 games, then just eight in their next 10. So even though the four dingers on this day were all of the solo variety, the surge was a sight for sore eyes -- and it came off a pitcher who came in having given up just four homers all year.

• Box score: Indians 5, Mariners 4

“We did what we do,” manager Scott Servais said. “We hit some homers. Unfortunately, they were solo homers.”

The Mariners need much more than that right now, because they are not playing well defensively and they are not defending late leads -- this marked the seventh time this season that a Mariners reliever has blown a save.

There was some unusual defensive moments in this one, most notably in the fourth, when Indians catcher Roberto Perez lined a single to right and Jake Bauers was hustling toward home from second base. Right fielder Jay Bruce’s throw home was on target, but catcher Omar Narvaez fielded it on a bounce and then immediately threw to second to get the advancing Perez instead of checking to see if he could tag Bauers. He got the last out of the inning, but the run scored to put the Indians up, 3-2.

“I think originally he was set up fine,” Servais said of Narvaez. “As the ball came, he kind of just disregarded [Bauers], he didn’t think he had a play. Jay made a really good, strong throw, and I certainly thought Omar had a chance to tag him out. He made a bad judgment.”

Those are the kind of “errors” that don’t show up as errors for the team with the highest error total in the game. But they count.

The Mariners’ other big issue is the bullpen. Would-be closer Hunter Strickland is hurt, four pitchers who have been designated for assignment by other organizations have been claimed in an attempt to patch things together, and the relief corps is generally rudderless.

Roenis Elias has been a rare source of reliability for Servais, and he was effective in relief of starter Mike Leake, aside from serving up a leadoff single to Francisco Lindor in the eighth. Leonys Martin moved the runner over on a sacrifice bunt, and Jose Ramirez struck out swinging. Elias was nearly out of the inning.

Servais, though, opted to bring in the right-handed Sadzeck to get the switch-hitting Santana to bat from the left-hand side. To be clear, Santana has been effective from both sides of the plate this season, but he came into this game with an .851 OPS against righties and a 1.033 OPS vs. lefties, so the move was defensible with regard to that split.

That said, walking Santana with the open base at first to get to Carlos Gonzalez, who entered with a .633 OPS on the year and was 0-for-3 on the day, was an option that the Mariners didn’t take. Sadzeck, one of the aforementioned acquisitions after he was DFA’d by the Rangers, had pitched well over his first nine opportunities this season. But he hung a slider over the heart of the plate, and Santana capitalized with the two-run shot to center that put the Indians up for good.

“We’re just giving guys opportunities and see if they run with those opportunities,” Servais said. “Connor has been throwing the ball well, he just made a mistake today, and we paid for it.”

The Mariners will keep experimenting with the ‘pen, because that’s their only option. They’ll hope they find a formula that works, hope the defensive play improves and hope the homers kept coming. But as Saturday demonstrated, homers can’t account for everything.