Gallardo will open up the series on Saturday for the Brewers, who will send Zack Greinke to the mound in Wednesday's regular season finale with potential playoff seeding on the line.
"It's an honor, definitely," Gallardo said Tuesday. "It's a privilege also. It just shows the amount of confidence they have in me. I was very excited once I heard that."
It's a balancing act for Brewers manager Ron Roenicke. He is trying to line up his starters for the playoffs while also looking to nail down home-field advantage in the first round.
"It kind of lined up that way, we thought," Roenicke said. "Yo threw a simulated game today, he'll throw another light bullpen Thursday and then he'll be ready to go. He's pitched really well lately and it just seemed to line up better that way."
Milwaukee entered Tuesday night's game against Pittsburgh one game ahead of Arizona for the No. 2 seed in the NL.
Roenicke said Greinke will pitch Wednesday no matter what -- but if the playoff seeding is resolved late Tuesday night, Greinke would likely pitch only a few innings.
In that scenario, Roenicke said Greinke could pitch Sunday's Game 2 on three days' rest.
"The plan is not for sure," Roenicke said. "But we have a lot options depending on what happens in the game today, what happens in Arizona and how much we need to win that game tomorrow and whether we're at home or not."
The Diamondbacks are finishing the regular season against the Los Angeles Dodgers.
If the Brewers are still playing for homefield advantage Wednesday and if Greinke is called on to pitch more than a few innings, he would pitch Game 3 and Roenicke would start Shaun Marcum in Game 2.
Marcum is 5-4 with a 4.81 ERA at home this season, and 8-3 with a 2.21 ERA on the road.
"(Marcum) may have to go the second game just depending on what happens today and tomorrow," Roenicke said. "And if he does, we feel comfortable with it. If you look just at the numbers, he has been better on the road but we like him. We think he's a great pitcher, I don't think the playoff atmosphere is going to bother him and it's nice to have him be flexible to do what we want."
Roenicke didn't want to skip Greinke's turn in the rotation.
"Zack doesn't want to go seven or eight days without pitching," Roenicke said. "He said he'd much rather come back on three days' rest than do that. When I talk about how hard it is to line up this stuff, that's the hard part. We're bringing him back on three days to try and set him up, that and to get him into the playoffs."
Gallardo is 17-10 with a 3.52 ERA this season. He's 2-0 in his last three starts, with double-digit strikeouts in all three of those games.
Gallardo pitched Game 1 in the Brewers' 2008 playoff series against Philadelphia after missing much of the season because of a torn right ACL. He gave up three runs in four innings and took the loss, then came back to pitch in relief in Game 4.
"I'm just very excited," Gallardo said. "I'm sure it's going to be a little bit different in '08."