"A ringing single for David Eckstein," Costas quipped at one point, "who, in my view, is the perfect size for an American male."
As the Padres knocked Parra around, Costas noted that some in the Miller Park crowd had begun to voice some displeasure.
"Bob, don't take it personally," Uecker said. "The booing will stop."
They will get serious for at least part of Friday's interview. Uecker, 75, discusses his more than 55 years in professional baseball, including his 40 seasons as the Brewers' radio voice. He talks about the health issues that forced him to miss a significant chunk of the 2010 season and to undergo heart surgery in April and again in October.
Costas will also explore Uecker's place in pop culture, including his starring roles in the film series "Major League," the TV series "Mr. Belvedere," commercials for Miller Lite beer and his frequent guest appearances on "The Tonight Show with Johnny Carson," who gave him the nickname "Mr. Baseball."
"[Carson] didn't know that much about baseball, but as we went along he let me do whatever I wanted," Uecker told Costas. "As a matter of fact, when I started doing the shows in New York, you get a script to follow and promote whatever you want to talk about. After about the 10th time I did the show Johnny said, 'Do you need this stuff?' and I said, 'No, I thought you did.' So from then on we pretty much just ad-libbed and went along, and whatever he said I just jumped in and went along with it."
Baseball remained Uecker's first love.
"Not bragging by any means, but I could have done a lot of other stuff as far as working in films go and working in television," Uecker says in Studio 42. "I had chances to do that stuff, but I like baseball, I really do. ... The Mr. Belvedere series was great, it lasted six years, but each March when we finished up in California, I couldn't wait to get to Arizona and get back to baseball and be around what I've been around for practically my whole adult life. After getting out of the service and going into baseball I never wanted to do anything else."
Of course, Costas and Uecker will have some fun.
"Any teammate of mine that had a kid and a boy that was capable of playing baseball, I think I set a terrific example of 'Don't do this' and 'Don't do that,'" Uecker told Costas. "And that's one of the things that I'm most proud of."
He added: "I was sent to winter baseball in June and July sometimes."
Prior to Studio 42 with Bob Costas, MLB Network will air Best of Hot Stove, its offseason nightly studio show, at 6 p.m. ET. The show features a look at the moves all 30 clubs are making and planning in preparation for the upcoming season.