CINCINNATI -- Since mid-August, the Nationals have been one of the hottest-hitting teams in the National League. And contributions from players like catcher Keibert Ruiz have keyed the resurgence.

On Saturday night, Ruiz and Lane Thomas homered, while Andrew Stevenson had a two-run single as the Nationals continued to swing hot bats vs. the Reds. But Nick Castellanos’ walk-off solo homer off Patrick Murphy defeated Washington, 7-6, at Great American Ball Park.

Ruiz homered for the second straight game, and was just inches away from another homer in the ninth when his drive down the right-field line went just foul.

The Nats scored seven runs Friday night, but lost in 11 innings. They were outslugged for a second straight night, leaving 10 runners on base.

Manager Dave Martinez believes one reason for the offensive outburst is that players are getting healthy after some issues with COVID-19, but also, it’s a testament to the work they are putting in with hitting coach Kevin Long.

“Part of the struggles that these guys had was that they were sick,” Martinez said. “They had COVID, it took a toll on their body. Once they got back on their feet, and got their work in with Kevin, they got better. … You can see the results.”

Washington's offense ranks second in the NL in runs scored (194), behind the red-hot Cardinals (206), since Aug. 15. Entering Saturday’s action, the Nationals ranked first in the NL in batting average, walks, on-base percentage and OPS in that same span.

But the hot bats weren’t enough for the Nationals on Saturday as starter Erick Fedde and the bullpen struggled to keep the Reds’ offense at bay.

Fedde, who had allowed nine homers over his previous five starts combined, did not allow a homer Saturday, but he was tagged for five earned runs in 4 2/3 innings.

“He couldn’t repeat his mechanics and got hurt,” Martinez said. “He just couldn’t locate his fastball, so he had to throw more curveballs.”

Thomas, who had no home runs when he was acquired from St. Louis in July, homered for the seventh time in September when he jumped on Tony Santillan’s first-pitch offering in the fourth.

In his last 10 games, Ruiz is 17-for-39 (.436) with three doubles, two homers, 12 RBIs and seven runs scored. He has struck out just one time in 41 plate appearances during the stretch and has hit safely in eight of those games.

“He’s a student of the game,” Martinez said. “He wants to learn every day. A lot of it had to do with slowing his feet down a little. The power was going to come. He’s seeing the ball a lot better.”

Another hot hitter is Josh Bell, who went 2-for-5 with a pair of singles in the loss.

Bell started the season on the COVID list and was batting .113 at the end of April and only .207 at the end of May. He’s up to .258 and rising.

“It’s just him getting ready on time,” Martinez said. “Seeing the ball a little better than he did earlier in the year. He’s swinging at more strikes. He’s gotten better at it. He’s fouling off good pitches. He’s hitting the ball hard.”

In the end, however, Saturday night was another tough loss punctuated by Castellanos’ walk-off.

“He took a big hack on that curveball [first pitch] and just missed it,” said Murphy, who relied on his curve in his 1 1/3 innings of work. “I got the fastball in, but he put a good swing on it and beat me.”