Shields allowed three hits over three scoreless innings with two strikeouts. His next start will come Monday in the season opener against the Dodgers.
"Three innings was kind of the ideal, I think I ended up throwing 30-35 [pitches]. I think I got some good work in today. I felt really good in my delivery today. Overall, my body felt really good. I'm ready to go," Shields said.
"He felt as though he's in a good spot," manager Bud Black said. "I thought his fastball had life to it, he had good location, threw some devastating changeups and some good cutters. He pounded the strike zone."
Samardzija allowed five runs on six hits in four innings with three strikeouts. He'll start Monday against the Royals to get the season underway.
"Everyone's feeling good right now and the team is where we need to be," Samardzija said. "I think everyone is ready to get this thing going, for sure."
Solarte had three hits for the Padres, while Carlos Quentin and Will Venable each drove in a run.
Adam Eaton, Micah Johnson and Tyler Flowers each had two hits for the White Sox.
Up next: Cactus League play comes to a close for the South Siders on Thursday with a game in Scottsdale against the D-backs at 2:10 p.m. CT. Jose Quintana gets the start, with Matt Albers and Kyle Drabek also on the list to pitch in a game that will be broadcast on MLB.TV and Gameday Audio.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.