"Don't give it up," he told himself. "Don't let No. 600 be a big one."
Two finely executed pitches later, the 25-year-old right-hander was pumping his fist in celebration after closing out the Tribe's 4-1 victory Tuesday night at Progressive Field.
Of course, Perez's journey to that moment was hardly textbook.
Brett Gardner and Derek Jeter notched two-strike singles to begin the ninth, with Jeter's drive down the right-field line advancing Gardner to third base.
Suddenly, Cleveland's three-run cushion didn't seem so cushy. And Perez, on a night he felt he had his "good stuff," was in a bad spot.
"I was talking to someone earlier today about the closer's mentality," said Perez, the Tribe's interim closer with Kerry Wood on the disabled list. "It's where you have to forget about all the other stuff and just start making pitches."
He made all the right ones against Nick Swisher, who fanned on four pitches, and Mark Teixeira, who popped up a first-pitch fastball to shortstop Asdrubal Cabrera for the second out.
Still, Perez's greatest challenge loomed ahead.
"I saw an opportunity to get a big hit," Rodriguez said.
And Perez? He saw a tendency he hoped to exploit.
"I saw how [starter Josh] Tomlin was working him away a lot the whole game with that cutter," Perez said. "I knew he might be looking for it, so I came inside."
Perez did just that with a 96-mph fastball on the inside corner for strike one.
"I was going to go back away," Perez said. "I had good stuff, so I was going to take my chances."
Much to Perez's delight, Rodriguez pounded the down-and-away slider into the glove of Cabrera, whose toss to second baseman Jason Donald retired Jeter for the third and final out.
"The No. 1 thing is to hit a ball hard somewhere," Rodriguez said. "A home run would have been fantastic, not only to get 600, but mostly to tie the game."
On this night, Perez ensured neither would happen.
"I was very confident," Perez said. "I knew that as long as I threw strikes, I had a good chance of getting out of it."