That changed in the final weeks leading into Spring Training. The Royals signed right-hander Jason Hammel, who will be either the No. 3 or No. 4 starter. And then they signed left-hander Travis Wood, who signed primarily to get a chance to be a starter again.
Suddenly, Karns was back to competing for a rotation spot along with Young and Wood.
"It doesn't scare me or change my approach," Karns said of the competition. "I feel like if you want to be a starter, you have to be one of the best five in camp.
"It doesn't matter if it's one of three guaranteed spots or one of five. I have to come in here and prove myself. Whether that happens or not is up to me."
In his first two outings, Karns has been nearly flawless. He retired the first 14 hitters he saw this spring and threw five straight scoreless innings before getting nicked for two runs.
"It's a nice competition," he said. "I enjoy it. I'm getting to know these guys. There's a lot to take out of this whole competition for this spot. At the end of the day, you have to compete and want the job.
"Whoever [wins it], at least I'm in that group."
So far, Karns is pleased with the early results he has shown.
"It kind of shows the hard work in the offseason is paying off," he said. "Now, I just need to maintain it and progress. I'm pretty excited about it."