The loss moved Leake to 0-5 with a 7.11 ERA in six starts this season. It will beg the question of whether he will get a seventh start in five days.
"We're all concerned. We've been concerned," manager Dusty Baker said of Leake. "As far as we know, he's healthy. He wasn't getting ahead of anybody. You pitch from behind, you're asking for trouble. He was either off the plate or over the heart of the plate, so we're concerned, big time. We're thinking and doing all we can do at this point in time. The rest of it is up to the player."
With the Reds playing their first game of a stretch of 20 games in 20 days, Leake did not do his team any favors.
While highly regarded rookie Bryce Harper was handed an 0-for-5 night, a good chunk of Leake's damage was done by a pair of Nationals hitters batting below .200 coming in -- Roger Bernadina and Danny Espinosa.
Leake was in a deficit almost immediately, as his second batter -- the .189 hitting Bernadina -- battled for 10 pitches and sent a 3-2 pitch into the right-field seats for a two-run homer.
"I was watching [Leake's] last outing, and what he throws to lefties," said Bernadina. "I know he's a sinkerballer, and he's got to get it up. He threw me a lot of pitches and I fouled a lot of them. He gave me one I could handle, and I hit the home run."
Next batter Ryan Zimmerman walked, and scored on an Adam LaRoche double to the left-field wall as boos quickly cascaded upon Leake, who needed 36 pitches to escape the first.
"I'm making it easy on hitters right now. I'm not making it tough," said Leake, who has allowed five or more runs in four of six starts. "I'm not getting them uncomfortable. I'm putting it in the hitters' hands instead of mine."
Wilson Ramos started the Washington second with a single, and scored from second base on a Bernadina RBI single to left field that made it 4-0. The hole became profound in the third when Danny Espinosa -- a .191 hitter coming in -- yanked a first pitch from Leake for a two-run homer to right field.
"He just wasn't making quality pitches," Baker said. "This was the thing you didn't want to happen in the first game of 20 in a row. I didn't want to use up all of my bullpen in this first stretch of games here. I ended up using most of our bullpen anyway."
Alfredo Simon gave up three hits, including LaRoche's RBI single to right field in the fourth. But it was a good night overall for Reds relievers, who kept the Nationals in check the rest of the way. Simon, J.J. Hoover, Jose Arredondo and Sam LeCure combined to retire a stretch of 17 out of 19.
Nationals lefty Gio Gonzalez, who took 14 scoreless innings over two career starts vs. the Reds into Friday, pitched five innings on Friday and gave up two runs and five hits with four walks and nine strikeouts.
The Reds' lineup had some chances to bail out Leake, but came up short as they were 3-for-14 with runners in scoring position.
In the fifth, after a Zack Cozart RBI single, Cincinnati had the bases loaded with one out but got nothing as Jay Bruce struck out and Scott Rolen popped out. And following a Ryan Ludwick RBI single which made it a four-run game in the eighth, the bases were again loaded with one out. Pinch-hitter Chris Heisey weakly popped out near the mound, and Cozart struck out to end the threat.
"At some point in time, when we have chances like this, our offense has to come back and snatch that ballgame away from them," Baker said. "We had a chance to do that."
Leake's next scheduled start is on Wednesday, when the Reds play the Mets at Citi Field. They have limited options, however. Veteran lefty Jeff Francis is scheduled to start on Saturday for Triple-A Louisville. Francis is 2-4 with a 4.15 ERA in seven starts, but has only nine walks compared to 43 strikeouts. Even though fans continue to clamor for Aroldis Chapman, he has been huge out of the bullpen and wouldn't be stretched out enough to start that soon.
These types of issues weren't expected for Leake after he led the Reds in wins and strikeouts last sesason.
"I'm sure he's at wit's end like we are," Baker said. "He's not used to getting beat up like this."
Leake had no answers for his performance this season.
"It's probably in the head somewhere," he said. "I just have to find it."