BOSTON -- Zach Plesac walked into the Indians’ clubhouse at Fenway Park following his Major League debut and found a handwritten note sitting at his locker.

Who could have already written to the rookie so soon after his first career start? It came from someone who had seen it up close and personal: the opposing pitcher.

“David Price wrote me a letter and left it at my locker,” Plesac said. “He told me, ‘Congrats on your debut. Good luck, kid.’ … It’s motivating. It means everything, really. It humbles me too at the same time.”

Hours earlier, as the rain poured down and drenched Fenway Park during Tuesday night’s 7-5 Indians win, Plesac ran out to the pitcher’s mound, shrugging off the weather and absorbing the moment.

The rookie right-hander dug his cleats into the dirt to establish his footing, threw seven warmup pitches, shook his shoulders loose and wiped the mound with his feet. Three years after being selected by the Indians in the 12th round of the 2016 Draft, Plesac was ready for his debut.

“I was ecstatic,” Plesac said. “Emotions were everywhere.”

Plesac faced reigning AL MVP Award winner Mookie Betts in the Red Sox leadoff spot. He delivered a 92.8 mph four-seam fastball for ball one, then threw the same pitch -- this time clocking 93.6 mph -- and got Betts to ground out to third. Just like that, Plesac had retired his first big league batter. He completed a 1-2-3 inning by striking out Rafael Devers and getting Xander Bogaerts to fly out to center.

“I was excited. First one [out], a little pressure eases off the shoulders a little bit,” Plesac said. “After the first one, I was like, ‘All right, we’re here. Out number one. Let’s get two.’ And just got locked back in.”

A rain delay lasting more than an hour interrupted the second inning and could have thrown off the momentum of a rookie pitcher in his first game, especially at Fenway. Plesac stayed loose during the delay by getting on the exercise bike and going in the cage. He allowed a double to J.D. Martinez immediately after the layoff but showed poise and got out of a two-on, one-out situation to hold the Red Sox scoreless.

Plesac looked sure of himself as he picked off Christian Vázquez in the third, retired the side in order in the fourth, and didn’t allow a run for the first five innings. His night came to an end when Devers tripled off a line drive to right field in the sixth (he would eventually score the first of three Red Sox runs in that inning).

“I thought he was very composed and competed like crazy,” Cleveland manager Terry Francona said. “That’s what you ask. He’ll have his time to make adjustments and things like that, but he competed like crazy.”

The right-hander concluded his debut with a line of four hits, one earned run, one walk and two strikeouts over 5 1/3 innings. He threw 86 pitches (57 strikes) and his pitch velocity averaged 89.5 mph, according to Statcast.

“I thought he accounted for himself really well,” Francona said. “There was a lot thrown at him. He’s making his debut at Fenway, it’s raining, he doesn’t know if we’re going to start on time and then there’s a delay. He attacked with his fastball to both sides of the plate. He threw some good changeups. I think we knew his breaking ball’s a work in progress. But he wasn’t scared. He didn’t back down from anybody. There was some solid contact and he kept pumping strikes.”

Plesac shared his special day with around 20 friends and family at the park, including his twin brother, who traveled from Alaska for the occasion. His uncle, former Major Leaguer Dan Plesac, sent him well wishes before the game.

He will save the note from Price, along with the scorecard and balls from his first pitch and first strikeout. It’s a personalized reminder of what he has achieved and the potential of what he wants to accomplish.

“I’m sure he’s just being the vet he is, taking care of the rookie here pitching my first game at Fenway,” Plesac said. “It was a class act. If he sees this, tell him I said, ‘Thank you.’”