OAKLAND -- A rough day became even worse for Angels right-hander Griffin Canning on Friday.

Canning scuffled through 3 1/3 innings before leaving with right elbow inflammation in a 13-3 loss to the A’s at the Coliseum. He was hit hard, allowing six runs on six hits and two walks, including a three-run homer to Max Schuemann on the final pitch of his outing. He said after the game that he felt something in his elbow when he threw sliders, though he wasn’t overly concerned about the potential severity.

"My slider was just bugging my elbow a little bit, so just give it a rest for the night and see how I feel tomorrow,” Canning said. “Not too much [concern]. Sometimes you just have to be smart and come out of the game."

After Schuemann hit an 0-1 changeup over the left-field fence to give the A's a four-run lead, Canning was met at the mound by manager Ron Washington and assistant athletic trainer Eric Munson. Canning then left the game with Munson walking with him back to the dugout. He appeared to shake his arm after giving up the homer, which was enough for the Angels to check on him.

Canning, pitching for the first time since July 10 because of the All-Star break, worked with slightly diminished velocity compared to his season average. His fastball was down 0.3 mph, as were his slider (87.1 mph average, down from 88 mph) and curveball (79.4 mph, down from 80.8 mph). But his issue was more about his lack of command -- not his stuff.

"He couldn't get ahead and he just couldn't put anyone away,” Washington said. "Just too many big innings and we couldn't stop them. So we just gotta keep going to the drawing board and see if we can get it right."

It marked the shortest outing of the year for Canning, who has had trouble pitching deep into games in recent starts. He went 4 1/3 frames in each of his previous two outings and has been in a rough patch after a solid stretch in May and early June. After posting a 7.45 ERA through his first six starts, he bounced back to record a 2.66 ERA in seven starts from May 5 to June 7. But he’s since registered a 6.25 ERA in the seven outings since.

"It’s just the ebbs and flows of baseball,” Canning said. “I just want to get back to being myself and having fun out there. Usually, things turn around when you do that."

Canning fell to 3-10 with a 5.20 ERA and has struggled to limit homers this year. He’s served up 19 homers in 20 starts this year, which is tied for the third most in the Majors. It’s something he also had an issue with last year -- but he still managed to post a 4.32 ERA in 24 appearances (22 starts) because he had a much higher strikeout rate and a better walk rate. Canning struck out 139 and walked 36 in 127 innings last year, but has struck out 73 and walked 38 in 105 2/3 innings this season.

He got through the first two innings unscathed but gave up three straight hits to open the third, including a go-ahead two-run triple to Lawrence Butler on a first-pitch fastball. Canning was able to strand Butler at third, but things unraveled for him the next inning. He gave up a one-out single to Zack Gelof, walked Seth Brown and then allowed an RBI single to Brett Harris. It set the stage for Schuemann's three-run blast that proved to be too much for the Angels to overcome.

"I just had scattered command and wasn’t getting ahead of guys,” Canning said. “I left that changeup up to Schuemann and he put a good swing on it. But yeah, it’s frustrating."

The Angels received solo shots from youngsters Zach Neto and Nolan Schanuel, but it wasn’t enough. Roansy Contreras allowed two runs over two innings in relief of Canning before lefty Matt Moore surrendered five runs, including two homers, as part of a seven-run sixth. It forced the Angels to use infielder Luis Guillorme to pitch the eighth -- and he threw a scoreless frame. But it was an otherwise tough night for the club’s pitching.

"It just wasn’t a good night," Washington said. “They banged us around the yard. We just couldn’t stop them."