In a matchup of the Nationals’ and Pirates’ top pitchers, the last thing Blake Butera wanted was what he did in the second inning. The Nationals manager ambled to the mound with one out in the frame to take the ball from Cade Cavalli.

Early in the Nationals’ 16-5 road loss to the Pittsburgh Pirates, Cavalli’s pitches and the strike zone felt like repelling forces.

It wasn’t for a lack of effort. Cavalli tried to regain feel for the strike zone. He kept his thoughts positive. Yet no matter how hard he tried, nothing quite worked.

“Sometimes, it’s like, ‘Alright, stay closed. Don’t think,’” Cavalli said. “Sometimes, it’s, ‘Try to power it in there.’ Whenever it’s going like that, you try a couple different things.”

Cavalli allowed four runs on three hits and three walks in a start that the 27-year-old deemed “very below average.” Through four starts, his ERA sits at 4.60.

After Cavalli exited, it only got worse. Jackson Rutledge, called up on Monday, had a similar outcome despite a different path. Rutledge, like Cavalli, had a strong first frame. But in his second, he didn’t miss enough bats.

Rutledge loaded the bases to open the sixth, then allowed a three-run triple to Bryan Reynolds, who scored on a Ryan O’Hearn double in the ensuing at-bat. Two more runs scored on RBI singles, followed by a three-run homer by Brandon Lowe.

“As [Rutledge] got into the inning, it looked like the stuff wasn’t maybe quite as sharp,” Butera said. “Didn’t have enough finish to it to put away those guys.”

The Nationals deployed outfielder Joey Wiemer on the mound in the eighth, capping a day defined by roster shuffling in the bullpen. Before the game, the Nationals recalled Rutledge and Orlando Ribalta to replace Cole Henry (right rotator cuff strain) and Ken Waldichuk (left forearm tightness), who were placed on the 15-day injured list. Waldichuk will likely need Tommy John surgery but is seeking a second opinion.

The Nationals optioned Rutledge back to Rochester after the loss, creating space for left-handed pitcher Mitchell Parker, on the team’s taxi squad, to get recalled and pitch as soon as Tuesday.

Washington faced an uphill battle from the start. Sure, they entered Monday’s game with the second-most runs scored per game in the majors. But the Pirates countered Cavalli with Paul Skenes, who is as much of an ace as they come. The reigning NL Cy Young winner struck out the first two batters he faced, James Wood and Luis García Jr., recording his 400th strikeout in just his 59th career start.

CJ Abrams was the only National who had success against Skenes. He hit a solo homer on a 100 mph fastball in the first frame to put Washington ahead. Abrams used a pitching machine from a short distance before the game to practice getting on top of Skenes’ fastball.

“No matter the pitcher, you always want to ... I mean they’re throwing the ball over the plate,” Abrams said. “You got to throw a strike to hit. Just kind of staying in my zone no matter who is on the mound.”

But herein lies the dilemma with Skenes: If a hitter gears up for a fastball, he can drop any of his secondary pitches to keep hitters off-balance. If a hitter waits for an off-speed pitch or breaking ball, Skenes can blow a fastball by anyone. His pitches move in all directions near the zone.

Only one other base runner reached against Skenes; Wood walked in the third. The Nationals finished 1-for-19 against the right-hander with seven groundouts, six strikeouts and five lineouts.

He exited after six innings to a rousing ovation from Pirates fans. The Nationals scored four runs in the seventh, but it was much too late. Pitchers don’t compete directly against each other. But facing Skenes leaves opposing pitchers with little margin for error.

Cavalli is the Nationals’ ace but still has a ways to go before establishing himself as one of the game’s elite. He’s relatively new to the big leagues with just 67 1/3 innings under his belt entering Monday.

His 2.51 ERA before Monday’s performance was a bit misleading — Cavalli had allowed a lot of base runners in his first three outings this year but escaped trouble, as evidenced by his 4.22 expected ERA from those outings.

After Cavalli retired the first batter of the second inning, 11 of the next 14 pitches he threw were balls. He walked the bases loaded. After a mound visit, Cavalli walked Oneil Cruz to tie the game at one. Then, Lowe and Reynolds hit singles to give the Pirates a 4-1 lead.

Cavalli struggled to locate anything besides his changeup. His knuckle curve landed in the left-handed batter’s box repeatedly. His sinkers landed near the dirt. More often than not, his fastballs missed well above the zone. Cavalli wasn’t the sole reason the Nationals fell on Monday night. Far from it. But his performance set the tone for what followed.

Butera said postgame that Cavalli’s pitches have been sharp all season. Yet Cavalli hasn’t been as efficient, struggling to get ahead of hitters. Strike throwing wasn’t a problem this spring. Neither Butera and Cavalli could diagnose why it’s now a problem but said they’ll watch video to search for a solution.

“Just was out of the zone an uncharacteristic amount,” Butera said. “Looked like he was fighting himself a bit.”