White Sox director of player development Nick Capra wrote via e-mail that Rodon had good fastball command, hitting 96 mph, and that the report was "encouraging."
"Just getting the rust off after a six-week break," Capra wrote.
"It's a good thing just to get started and get your feet wet," said White Sox manager Robin Ventura of Rodon. "It's a pretty exciting time for him. We're just happy to get him going and get him in the fold."
Rodon is expected to make another appearance in Arizona and then get promoted to Class A Winston-Salem of the Carolina League. His chances to reach the Majors out of the bullpen with the White Sox this season remain a question.
"They haven't said anything. This is his first taste of being in professional baseball," said Ventura of expectations for Rodon. "We'll have talks as he goes along, but for right now, the focus is just on what we've got here and continuing to try to win games with these guys.
"If he does something that makes them push him up here, then that will happen. We haven't talked about it."
Scott Merkin is a reporter for MLB.com. Read his blog, Merk's Works, and follow him on Twitter @scottmerkin. This story was not subject to the approval of Major League Baseball or its clubs.