BOSTON -- The Red Sox didn’t expect Andrew Cashner to be a savior when they acquired him from the Orioles three weeks ago, but they were plenty confident he could provide some much-needed stability in the fifth spot in the rotation.

Five starts in, Cashner has pitched at a level far lower than he did in Baltimore, and his woes continued in Tuesday night’s 6-2 loss to the Royals at Fenway Park.

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After opening the outing strong with three scoreless innings, Cashner was hit hard the rest of the night, giving up three homers and six earned runs and exiting after 5 1/3.

Rick Porcello had snapped an eight-game losing streak for the Sox with a much-needed quality start on Monday night, and the hope was that Cashner could do the same.

Instead, the righty gave up four runs or more for the fourth time in his five starts in Boston.

“I thought I had good stuff. Made three mistakes,” said Cashner. “They hit three home runs. That's kind of the way it goes. But this is a team that we've got to beat. I've got to be better."

With the Orioles, Cashner was 9-3 with a 3.83 ERA while giving up 11 homers in 96 1/3 innings. It has been a different story with Boston, where he is 1-4 with a 7.53 ERA while giving up seven homers in 28 2/3 innings.

"I just think I just made too many mistakes and they've hammered them here when I've made them,” Cashner said. “But I've pitched up here for a long time. So I mean this has probably been one of the toughest stretches of my career. I've just got to get back to what I do well. Get back to that and get them on Sunday."

Jorge Soler did most of the damage against Cashner, hitting a pair of two-run homers to give him 31 on the season. The light-hitting Ryan O'Hearn (.175 average) added a solo shot in the fifth.

The Red Sox had the first lead of the game thanks to an Andrew Benintendi RBI single in the bottom of the third.

What they needed in the fourth was a shutdown inning. Cashner put away the first two batters with no trouble, but his night went downhill after a walk to Hunter Dozier. Soler stepped up next and obliterated Cashner’s first-pitch fastball over everything in left field -- the Monster, the billboards and for all anyone knows the entirety of Lansdowne Street.

“The walk before the homer with two outs, and he misfires,” said Red Sox manager Alex Cora. “It’s one swing for two runs. As you know, in this game you can’t give the opposition one extra out or one extra hitter with two outs. Lineups are going to make you pay.”

The Red Sox have paid continually of late, losing nine of their last 10 to fall 6 1/2 games back in the AL Wild Card standings.

“We can’t get the opposition to keep the ball in the ballpark and we’re paying the price,” Cora said. “That’s the case with Cashner.”

Entering Tuesday, Cashner had 135 starts since Statcast tracking began in 2015 and had allowed a total of four homers struck at an exit velocity of 110 mph or more in that span. The Royals hit two at that speed against him in the loss.

The Red Sox don’t see much of a dropoff in Cashner’s overall stuff. Instead, they see isolated mistakes. But that doesn’t make it any less costly.

“We trust him,” Cora said. “Stuff-wise, he’s still throwing the ball well. If we have to make adjustments mechanically, we’ll take a look at it, but I do feel it’s just location. We saw the walks in the previous one and today just three pitches. That was it right there.”

Does Cashner feel it is mechanics?

“I don't really know,” he said.

There’s not much Cashner can do except go back to the drawing board and try to rediscover the form he had in Baltimore.

“Yeah, it's been tough,” Cashner said. “I think over the course of my career I've been good at limiting damage. I haven't done a good job of that since I've been here. Mistakes are too up in the zone. Haven't really done a lot of things well but we still have a month and a half left."

“There’s a reason we brought him here,” said Cora. “We believe he’s a good pitcher. We see flashes of his stuff and what he can do.”

With where the Red Sox are in the standings at this point in the season, they’re going to need more than flashes from Cashner -- not to mention the entire starting rotation.