BOSTON -- Cristopher Sánchez's pitch had barely hit rookie catcher Rafael Marchán's mitt when Bryce Harper started his slow stroll to the mound from first base.

With the Phillies holding a four-run lead, Sánchez had just thrown his sixth straight ball and found himself behind in the count with runners on the corners and only one out in the fourth inning. Marchán trotted out to join the duo -- as did shortstop Bryson Stott and second baseman Whit Merrifield -- but it was Harper who did all the talking.

Sánchez nodded silently while repeatedly patting Harper's leg with his glove. He then immediately pumped in four straight strikes to escape the inning while limiting the damage to just one run off a sacrifice fly.

Sánchez, however, wasn't nearly as fortunate one inning later. The left-hander allowed three straight hits to start the inning before being lifted with nobody out in what unraveled into a five-run frame in the Phillies' 8-6 loss to the Red Sox at Fenway Park.

“His command was off a little bit,” manager Rob Thomson said. “He wasn't commanding his fastball and he wasn't commanding his changeup, so they were taking a lot of balls in the dirt.”

Though Sánchez was hit hard early and often, the bigger surprise was that inability to find the zone. He threw just 35 of his season-low 67 pitches for strikes, resulting in a season-worst 52.2% strike rate.

Sánchez walked two batters, uncorked one wild pitch and tallied only two strikeouts over four-plus innings, all while allowing a season-high-tying four earned runs.

So what felt off for Sánchez?

“All my pitches, my command -- everything,” he said.

In stepped Harper.

At the time of Harper's visit, Sánchez had thrown only 25 of his 55 pitches (45.4%) for strikes. That was a surprising number from a pitcher who had thrown 68.6% of his pitches for strikes since the start of May -- the fifth-highest strike rate of the 116 big league starters to throw at least 500 pitches during that span.

Harper's unusual move provided a reprieve, however temporary.

“That was great,” Thomson said. “From that point on, the last two hitters in the fourth, that was Sanchy -- throwing the ball with conviction, throwing strikes, using his changeup. ... So whatever Harp said was the right thing, and Sanchy got after it.”

So what did Harper say?

“I just wanted to make sure he had all the confidence in the world to make pitches,” Harper said. “Marchán called time right there and I just wanted to run over there and reiterate whatever he was going to say.”

But it was Harper who ended up doing all the talking.

“He was just motivating me,” Sánchez said. “Just telling me to focus and throw the ball for strikes.”

Obviously, that pick-me-up would typically come courtesy of three-time All-Star catcher J.T. Realmuto. But on the same day Realmuto underwent successful right knee surgery in Philadelphia, Harper embraced the opportunity to display some veteran leadership.

“I don't think you can really replace a J.T., you know?” Harper said. “He's one of the best in the game for a reason. He does a great job back there, calls a great game and makes sure guys are comfortable.”

That’s something that the Phillies are confident Marchán will continue to get better at with more reps. Wednesday marked just his 17th career start behind the plate -- and his first big league action of any kind since 2021.

“Obviously,” Harper said, “we've got [Garrett Stubbs], who does a great job out there, and the more and more that Raffy catches, the more comfortable he's going to get, too.”

To be clear, nobody -- Harper, Thomson nor Sánchez himself -- put any of Sánchez's off night on the catching situation. As Sánchez acknowledged, he just simply did not have a feel for any of his pitches. (And it’s worth noting that this was his first start in eight days due to the off-days surrounding the London Series.)

In other words, a night like this was bound to happen eventually. But even with the rare misstep, Sánchez still holds an impressive 3.07 ERA. He's allowed only one home run over 70 1/3 innings in 13 starts.

As Harper told Sánchez on the mound, they have all the confidence in him.

“That's just kind of how baseball works, right? That's how pitching works,” Harper said. “All in all, next time he gets out there, he's going to be just fine.”