ANAHEIM -- It was just one bad inning for lefty Patrick Sandoval on Sunday.

But with how things have been going for the Angels this season, it was enough to hand them a 4-2 loss to the Royals in the series finale at Angel Stadium. Sandoval pitched into the seventh inning for a second straight start but was plagued by a four-run fourth and some tough luck in the seventh.

Sandoval, who was coming off throwing seven scoreless frames in Pittsburgh, didn't walk a batter in his six-plus innings but gave up a career-high 11 hits, including five straight to open the fourth. Despite the high hit total, it was still another positive step for Sandoval, who had a 6.33 ERA in six starts in March/April but has posted a 3.00 ERA with 20 strikeouts and three walks in 18 innings over three May starts.

"The takeaway from his start is that he should be pleased," Angels manager Ron Washington said. "It was one inning. Sometimes that happens to you. They strung some hits together. [Salvador] Perez hit the double and they just singled us to death after that. But he stayed in there and he got us through six innings."

Sandoval was still plenty frustrated after his start, as he didn't like his pitch selection in the fourth. He cruised early, but Perez sparked a big inning for Kansas City with a leadoff double on an 0-1 sinker.

Nelson Velázquez and Freddy Fermin followed with singles before Dairon Blanco reached on a bunt single after a Royals challenge overturned the initial out call. Former Angels outfielder Hunter Renfroe came through with a two-run single on a 0-1 sinker before Michael Massey plated a run on a sacrifice bunt. Sandoval was particularly irked by Renfroe's single, as he threw consecutive sinkers to Perez and Renfroe after getting ahead, but it didn't work out.

"I made some really stupid decisions in the fourth that led to the four runs and I have to live with that," Sandoval said. "Just doubling up to Renfroe on the fastball and a couple other pitches I shouldn't have thrown."

First-pitch strikes have been an issue for Sandoval this season, but that inning was different. He got ahead of the first six batters faced that frame with a first-pitch strike but couldn't quite execute from there, which made it even more aggravating.

"I got ahead of them and just made some bad decisions there," Sandoval said. "I gave them better odds than I gave myself."

However, Sandoval settled down and got through scoreless fifth and sixth innings before returning for the seventh. But he suffered from tough luck, as Maikel Garcia reached on an infield single and Bobby Witt Jr. got on via an error by shortstop Zach Neto.

Sandoval was removed after six-plus innings and 95 pitches, but reliever Hunter Strickland came in and got out of the jam. Strickland has now turned in 10 straight scoreless outings.

"He's been doing a great job," Washington said. "He has a tremendous slider. And he has some heaviness on his fastball. And he came in and he did exactly what he needed to do. Got us out of that with minimal damage because he came in with nobody out."

Sandoval, who fell to 2-6 with a 5.00 ERA in nine starts, believes he's on the right track after making recent adjustments. He struck out just three but was pleased with no walks.

"I'm in the zone way more," Sandoval said. "Walks are way down. Punchouts had been up prior to this game. All encouraging signs."

But the four runs were enough damage, as the offense has struggled with numerous injuries to key players. They scored just once against right-hander Seth Lugo, who went eight innings and struck out 12.

The lone run came in the sixth inning on an RBI double from Willie Calhoun. Calhoun later added a solo shot in the ninth off closer James McArthur and has been off to a strong start since being called up on May 1, but it wasn't enough.

"You hope to create some situations where you can do something to create some offense but we haven't been putting ourselves in position to create much offense," Washington said. "We just have to wait until these guys get it together. They're out there fighting their butts off. We just haven't been able to consistently string things together."