Well, sort of.
Last September, after he had completed his season with Double-A San Antonio, Kelly and fellow pitchers Joe Wieland and Robbie Erlin joined the team in Colorado for the final two weeks of the regular season -- not on the roster, but as bystanders charged with taking in as much as they could while watching veteran players go about their business.
"I think it was valuable for those guys," said Padres manager Bud Black.
No more so than for Kelly, who tossed six scoreless innings in his Major League debut on Monday against the Braves. His second start will come at Coors Field, where he tossed a simulated game last September.
Asked about his experience last September, Kelly said it was beneficial for him to learn and watch.
"I think it was a great experience, because you didn't come in here having to worry about playing that day," Kelly said. "You could see how everyone goes about their business. And with the starting pitchers, you could watch whoever was starting for the whole day, when they go into their meetings, going over scouting reports ... really just how they go about preparing themselves.
And while he was still nervous before his start against the Braves, he felt better prepared for what might occur, thanks in large part to his unofficial time in the big leagues late last season.
"It was huge. You learn so much by watching," Kelly said. "You get to sit and listen to the veteran guys who have maybe faced a hitter hundreds of times. You watch what the hitters are doing, too. And you start thinking about what you want to do to them."