Carlos Villanueva, who could step in as the fifth starter for the Cubs, gave up three runs on three hits and three walks over four innings, striking out three.
Villanueva just shrugged off the outing.
"My stuff is crisp," Villanueva said. "I'm getting to the point where I feel confident I can get guys out, and I'm not making the mistakes I was early. I feel good, and can't wait for this thing to get started."
However, he's still not sure whether he'll be in the Cubs' bullpen or rotation once the regular season begins in one week.
"It's the same thing you guys know -- you probably know more than me," Villanueva said.
Nope. All Cubs manager Rick Renteria would say before the game was that the candidates for the job are "all still here." That includes Villanueva and lefty Chris Rusin.
"I'll probably have a locker tomorrow," Villanueva said. "It's basically the same -- prepare. Maybe tomorrow I'll hear something. I talked to [pitching coach Chris] Bosio after the game, and we feel good about where I am right now. It just gets a little boring going out there. It doesn't really count right now, so for me, at this stage of my career, I feel ready for the season."
Emilio Bonifacio tripled to lead off the Chicago first and scored on Donnie Murphy's groundout against San Diego starter Eric Stults. But the Padres tied it in the second when Jedd Gyorko singled and scored on Smith's double.
Medica, battling for a spot on the Padres' bench, broke the tie in the fourth. With two outs, Smith walked and Medica launched a 1-1 pitch from Villanueva into the left field berm.
Jose Veras, the Cubs' closer, was roughed up in the fifth. Everth Cabrera singled, Will Venable walked and Chase Headley followed with a RBI double. One out later, Gyorko was hit by a pitch, and Smith added an RBI single.
Stults, who will be the Padres' No. 4 starter, scattered five hits and walked one over 5 2/3 innings, striking out three.
Padres closer Huston Street struck out two in a perfect ninth.
On deck: Tsuyoshi Wada, who was released by the Cubs on Sunday and signed a Minor League contract to return to the organization on Monday, will start the first of two split-squad games on Tuesday. Wada will start at 2:05 p.m. CT at Cubs Park against the Angels. That game will be available on MLB.TV as well as an exclusive free audio webcast on Cubs.com. C.J. Edwards, a top prospect who was acquired from the Rangers in the Matt Garza deal in July, will lead another squad at 8:05 p.m. CT against the Padres in Peoria.