CINCINNATI -- Brett Kennedy wasn't himself on the mound at Great American Ball Park on Friday night. Whether it was the long rain delay or just a mechanical issue, it was a rough outing for the 24-year-old right-hander.

"It was pretty evident early his velo wasn't where it had been [in prior outings], and his command wasn't there," said Padres manager Andy Green after the 12-6 loss to the Reds. "It wasn't like they were really close misses today, he was missing fairly significantly."

Kennedy walked four and allowed four earned runs. He was lifted after only 44 pitches, making for a long night for the Padres' bullpen, which allowed eight earned runs in 6 1/3 innings, including a pair of homers by Phillip Ervin and Scott Schebler's grand slam in the sixth inning.

On the bright side for San Diego, Hunter Renfroe continued to make his case for a starting outfield spot next season with his 21st home run, and Eric Hosmer added his 14th homer, his first since Aug. 21, in the eighth.

But Green seemed concerned about Kennedy following the game, although he hadn't yet spoken to him or the training staff. After posting a 2.81 ERA in his previous three starts, including his first career victory, Kennedy hit a bump in the road on Friday.

"The ball just wasn't coming out of my hand right," Kennedy said. "It's something I haven't dealt with before. I felt like I always do. No excuses, my mechanics were just not there. It made it really tough on our bullpen."

Following a two-hour, 37-minute rain delay due to torrential rain, the Padres greeted Reds starter Anthony DeSclafani with four straight one-out singles, capped by William Myers' hit up the middle, to produce two runs in the first.

Matt Strahm replaced Kennedy and allowed Jose Peraza's bases-loaded double to clear the bases and put the Reds ahead, 4-2.

Kennedy allowed one hit, but he was charged with four earned runs in 1 2/3 innings. The four walks equaled his total over the previous two outings.

"From a baseball perspective, we thought it was prudent to go ahead and get to the bullpen as soon as possible," Green said. "We hope he's fine."

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Renfroe homered for the second straight night in the third inning. He has 14 homers since the All-Star break, and six in his past 11 games.

After Manuel Margot's RBI double drove home the tying run in the fourth, Ervin's fifth homer, off Strahm, put the Reds ahead, 5-4. Ervin added a two-run homer in the seventh off Miguel Diaz for his first career multi-home run game.

Rowan Wick allowed five runs in 1 1/3 innings, including Schebler's second career grand slam in the sixth inning, giving the Reds a Major League-best 10 grand slams this season, which also is a single-season franchise record.

MOMENT THAT MATTERED

It was a one-run game in the sixth inning when a pair of bunt singles led to a five-run frame for the Reds. On Ervin's suicide squeeze, with one out and runners at the corners, Luis Urias failed to cover second base. The next batter -- Michael Lorenzen -- bunted toward Wick, who wasn't quick enough off the mound to field the ball. Schebler followed with his grand slam. The Reds have used the bunt as a weapon under interim manager Jim Riggleman, and Green took responsibility for his team not being better prepared.

"It's a lesson that little bunts can lead to big innings," Green said. "We have a lot of young kids up here, but we can't use that as an excuse. We'll work on the bunt defense. There's a conversation with a young second baseman who probably hasn't seen a lot of suicide squeezes in Triple-A this year. We have to get off the mound a little quicker. I have to take ownership with not setting us up to defend it better."

UP NEXT

Left-hander Robbie Erlin is looking to snap a personal two-game losing streak when he makes his ninth start of the season against the Reds on Saturday at Great American Ball Park. Erlin is starting against the Reds for the first time -- he has one career appearance against them. The Padres will face right-hander Matt Harvey, who will make his 21st start for the Reds since being acquired in May. First pitch is set for 1:10 p.m. PT.