His immediate concern is the game being played, and not worrying about what may happen tomorrow.
"I don't worry about tomorrow," Guillen said. "Maybe tomorrow, we'll be down 30 runs in the eighth. Maybe we'll be up by 30 runs in the eighth. I don't try to think about the next day when we're not there."
It's that philosophy that will make figuring out the ninth inning a challenge for the Marlins.
Ideally, the club would like for Heath Bell to be the closer. But after a rough first half, the veteran right-hander is being asked to earn the position again.
On Saturday night, in a 2-1 win over the Nationals, Steve Cishek went 1 2/3 innings for the save. It was the team's first five-or-more-outs save since Burke Badenhop got six outs on April 14, 2010, in a 5-3 win over the Reds at Sun Life Stadium.
Cishek got two outs on 12 pitches in the eighth inning, and he went back out for the ninth, throwing 28 total pitches.
"Their best hitter comes [up] in the eighth, it has to be Cishek," Guillen said. "If not, my best option is Bell out of the bullpen."
Cishek accepted the extra workload.
"When I came into the dugout after the first two-thirds of an inning, [Guillen] told me I was going back out," the 26-year-old right-hander said. "It got me fired up. I went through the process of getting mentally prepared to go out and throw another inning."
The question now is when Cishek will be available next. The 28 pitches were his most since throwing 36 on June 23 against the Blue Jays. He also woke up on Sunday morning sick, vomiting before he got to the ballpark. Because Cishek wasn't feeling well, he was sent home before Sunday's game.
Cishek noted that the uncertainty of when he will enter games is nothing new.
"I approach it like I approached my job before," he said. "I was the seventh-, eighth-inning guy to start the year. I never knew when I was going in from the seventh inning on. I do the same routine I've always done since the beginning of the year. I'm always mentally ready to go in from the seventh inning on, so I don't make it hard on myself."