The area native hit a home run during Wednesday's intrasquad action at the Urban Youth Academy and was the only catcher during Thursday's game at Minute Maid Park who didn't allow a passed ball.
Murillo's under-the-radar status could be forgiven, considering who was on his high school team. He caught Kohl Stewart, the Twins' top selection in the 2013 First-Year Player Draft.
"It never helps to lose a guy who throw 96, but Kohl was the best around as a pitcher and teammate," Murillo said. "You get better being around the best."
Stewart is actually responsible for Murillo getting behind the plate. On their high school team, no one could catch the hard-throwing right-hander.
So Murillo threw on some gear at the request of his coach one day, but he received no adjustment period behind the dish.
"The first time I got back there, I had to see upper 90s, 96-97, from Kohl," Murillo said. "My hand hurt a little. It was a challenge."
While attending a Perfect Game Showcase in Fort Myers, Fla., earlier this month, Murillo briefly reunited with his now-famous friend.
Stewart, who inked a $4.5 million signing bonus with Minnesota last month, was pitching there in the Gulf Coast League as his pro career gets under way.
"It was very fortunate while were out there, since we got to talk to him, and he came to the beach house where we were staying," Murillo said. "He told us all about the Minor League routine and what to expect."
Already on the heels of a state title at St. Pius, Murillo was asked to undertake the most demanding position on the diamond. But he delivered, making no errors behind the plate in 2013 as the Panthers nearly defended their title, losing in the state finals.
Murillo was a mainstay in the lineup, belting seven home runs and collecting 28 RBIs while hitting .302.
That set the stage for an invite to this week's Breakthrough event, which is part of a combined effort by Major League Baseball and USA Baseball to spotlight and bolster the involvement of urban youth in the sport.
Murillo's breakout week at the Academy seemed only fitting, considering he's been generous with his time there.
The 17-year-old has been a fixture, volunteering for various youth camps held at the park, which is run by the Houston Astros and Major League Baseball.
"Basically, the UYA will hold camps for urban, inner-city kids and we have them come out and set up stations," he said. "One day will be defense, the next will be offense and we just do little drills to teach them the game. I just like being around baseball, so it's fun."
From that venue on Wednesday to Minute Maid on Thursday, it was just another old stomping ground for the Houston native.
Murillo grew up an Astros fan and was a regular in the Minute Maid stands growing up, though his baseball schedule has gotten in the way of that during recent summers.
"I haven't been able to come to as many games, because my personal baseball schedule keeps me busy," he said. "But whenever they won the  NL pennant, I remember being here all the time. Those were the good times for the team."
And speaking of that schedule, Murillo has stayed busy all summer, hardly enjoying time off like a normal kid. In a few weeks, he'll head up to New York for another showcase, where he'll get to play at Citi Field.
This is after he's already attended several prep tournaments, an Area Code Baseball series and college camps.
"It's normal for a baseball player, not most people," Murillo chuckled. "I wouldn't trade it."
Astros general manager Jeff Luhnow said Murillo was among a handful of local players at the Breakthrough event that the clubs local area scout has his eye on.
"I talked to our area scout [before watching the Showcase game at Minute Maid on Thursday], and he's pretty excited about some of them," Luhnow said. "Certainly the tie goes to the local guys in our case, so we'll make sure we know as much as possible about [Murillo]."
For now, though, the catcher is plotting out colleges. Schools like Ole Miss, Sam Houston State, Oklahoma State and Texas State have all been in contact, and he hopes to have a verbal commitment in place soon.
But if a Major League team comes calling next June during the Draft, especially if it were the Astros, Murillo said he'd have a hard time turning them down.
"It's been my dream," Murillo said of getting drafted. "You grow up around baseball and watching big league games, and that's the goal, to get there."
After a week in which he proved himself against some of the brightest young talent in the game, Murillo might be one step closer to that goal.