Twenty minutes and eight pitches into Game 1 of the National League Division Series between the Reds and Giants, however, Latos realized quickly this day was going to be anything but ordinary.
The Reds' best-laid plan went awry almost immediately. Johnny Cueto recorded just one out, exited with back spasms and suddenly, the Reds were scrambling for Plan B.
Latos, who had never made a relief appearance in his big league career -- 105 appearances, 105 starts -- was part of that plan. And it worked. He provided four crucial innings, holding Giants hitters in check from the third through the seventh, allowing only a Buster Posey solo homer during a 57-pitch outing.
"Here is a guy sitting back, relaxed, thinking he was going to pitch next week at home, and now all of a sudden, boom, this is his first playoff game," Reds manager Dusty Baker said. "It was a great feat by him."
Baker and Reds pitching coach Bryan Price prepared Latos as best as they could, given the time restraints. They first turned to reliever Sam LeCure to get them through the first and second innings, giving Latos time to get ready for a pseudo-start of sorts. Although he was to enter the game in the third, Latos went through a few preparatory exercises in the clubhouse, similar to what he might do on a day he's actually scheduled to start.
That part was key for Baker, which was why he didn't turn to Latos immediately following Cueto's exit.
"As a starting pitcher, you have a day or two to get yourself ready mentally and also give him plenty of time to get ready in the bullpen," Baker said. "As a reliever, it takes you a lot less time to get going. With that, we were going to determine that, at that point in time, we were going to give Sam those two innings."
Latos did his best to forget about the 20-pitch bullpen and the weight-lifting session from earlier in the day, activities no pitcher would undertake on a normal day he's starting. He went to the clubhouse, put on his spikes, did some stretching, got loose and started warming up.
"It's a little out of routine, a little uncomfortable, but I mean, it was fine," Latos said. "They gave me the right chances to get into the game."
From Price's vantage point, turning to Latos to absorb the majority of the innings, on three days' rest, was an easy decision.
"You can look at it two ways," Price said. "You could make an excuse for why you failed or give yourself reason on why you're going to succeed. There was no hesitation from Mat. He wanted the ball and took it and did a great job."
Latos last appeared in relief when he was a Class A pitcher in 2009, and the only reason he didn't start that game was because he had just gotten off a plane from Arizona and got to the ballpark late. He threw seven innings that day.
A Minor League environment obviously cannot compare to the pressure of postseason baseball, on enemy territory, in a short series where there's such a small margin for error. Brandon Phillips admitted he said to himself, "We're done," when he watched Cueto walk off the mound eight pitches in. Random cheers among the crowd at AT&T Park suggested Giants fans were thinking the same thing.
But Latos, formerly a budding young star with the Padres before he was traded to Cincinnati, had something different in mind. It helped that he has always pitched well at AT&T Park, as evidenced by his 1.87 ERA here. He also took a perfect game into the sixth inning in San Francisco a couple of years ago.
"I'm comfortable in this ballpark and I've pitched here for 2 1/2 years," he said. "It wasn't any surprise, other than me pitching. I know what to expect from this ballpark. I know what to expect from this lineup that I was facing. I've had great success against them."
"He thrives in this ballpark," Price said. "He likes the negative energy and he feeds off of it."
Latos' four-inning appearance essentially erases his availability to make his actual scheduled start in Game 3 in Cincinnati on Tuesday. But while it's still to be determined, Cueto could be ready to pitch again by then, which would make what initially appeared to be a potentially catastrophic injury to Cueto nothing more than a last-minute game of switcheroo between two pitching teammates.
But even if Latos doesn't make another appearance in the Division Series, he's clearly made his mark on this leg of the postseason.
"I don't think we could have expected on three days' rest and having already thrown a bullpen that he was going to be able to give us four innings of one-run baseball in this type of environment," Price said. "I couldn't be more impressed."