What an appropriate place for the Brewers to play their first doubleheader in two years: Wrigley Field, where the Ernie Banks statue outside is engraved with his famous line, "Let's play two!"
"I don't think I've been involved in a split doubleheader in over 10 years," Brewers manager Ron Roenicke said.
He will be involved in one Tuesday, when the Brewers send Yovani Gallardo to the mound for Game 1 and Tyler Thornburg for Game 2. Both have had uneven seasons -- Gallardo has been struggling with velocity and command, while Thornburg is finding himself stuck somewhere between a starting role and relief for the second straight year.
"For him to be effective, he's going to have to get his secondary stuff working," Brewers pitching coach Rick Kranitz said of Thornburg, who will be pitching for the first time since July 23 and starting for the first time since June 25 at Triple-A Nashville. "He is a 'stuff' guy. It's probably the hardest thing any young kid can [go through], is not pitch and then go in there. But that's part of being a big leaguer -- you've got to be ready when called upon. That's a tough job."
It remains unclear if the highly touted Thornburg will be a starter or a reliever. At some point, the Brewers want to move him back to a starting role, but for now he is needed in the bullpen.
"I think he's settled in to what he's done, which is come in and pitch in the middle of the game and keep us in games," Kranitz said. "I think he's done a nice job. I don't think you ever give up on a guy as a starter with his stuff, but there's no harm in getting experience at the big league level doing what he's doing. Ultimately, what it comes down to is guys believing they can get guys out. … Hey, it's the same thing Marco [Estrada] did two years ago. He jumped in and showed that he could do the job."
Estrada, on the disabled list with a hamstring injury, began a rehab assignment for rookie-level Arizona on Monday. If he returns as scheduled after three starts, Thornburg may be sent back to Nashville to pitch in the rotation.
Meanwhile the Cubs will counter with Carlos Villanueva in Game 1 and Jake Arrieta in Game 2. Villanueva is 2-7 this season with a 4.23 ERA, and last saw Milwaukee on June 26 -- an outing in which he threw one inning of relief.
Brewers: Milwaukee calls up Gennett for extra bench support
With MLB rules allowing teams to promote an extra player for scheduled doubleheaders, the Brewers will call up second baseman Scooter Gennett.
He is expected to start one of Tuesday's games, but will be sent back to Nashville on Wednesday.
In a 17-game stint earlier with the Brewers from June 3-26, Gennett went 9-for-42 for a .214 batting average. His nine hits included a double, a triple and a home run and five RBIs.
Cubs: Arrieta to make debut Tuesday
Arrieta, who was acquired form the Orioles on July 2 in the Scott Feldman deal, will make his debut as a Cubs pitcher on Tuesday night in Game 2 of doubleheader.
The right-hander had three stints with the Orioles this season prior to the trade. During that time he went 1-2 with a 7.23 ERA in five starts. But with the Cubs, he is determined to stay in the starting rotation.
"It was almost like a weight off my shoulders, really," he said of the deal. "I felt like I was able to do a lot of good things over there, but there were some things that kept me from being able to do it on a consistent basis. My time there was great, and I wouldn't change it for the world. There came the point where they felt a move needed to be made to better their team and better this team as well.
"I've got a lot to offer," he said. "I feel I'm a guy who can go out there and be a bulldog and pitch deep in games, and I know I can do it on a consistent basis so it's just a matter of finally going out there and doing it."
• Anthony Rizzo's 30 doubles this season prior to August 1 are the most by any Cubs player since Alfonso Soriano's 30 doubles in 2007. Heading into Monday night, Rizzo was tied for second in the National League.
Kelly Erickson is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.