The right-hander struggled adjusting back to a starter's role with Kansas City this season, going 6-10 with a 5.67 ERA and 1.76 WHIP over 24 starts. Davis, acquired from Tampa Bay in the offseason, pitched in both roles during his career with the Rays, and was a big weapon out of the bullpen for them in 2012.
Davis had a 2.43 ERA and 87 strikeouts in 70 1/3 innings over 54 appearances last season, and Kansas City is hoping he can rediscover that form.
"He had some struggles, but he also had some very good games," said Yost. "Transitioning again from starter to reliever, I think he learned a lot. It's just getting consistent and having a solid approach every time he goes out."
Yost thinks it's important that Davis understands the mental differences between starting and relieving.
"The stuff is definitely there, but it's a tough transition," Yost said. "As a reliever, you are coming in and blowing it out for two innings. As a starter, there is more strategy involved in the way you command your pitches and throw the ball.
"I think, at times, he [was] caught between the two mentalities. But I think he is going to be fine."
The Royals will also recall righty Louis Coleman from Wilmington on Tuesday. Coleman has spent the majority of the season at Triple-A Omaha, and sports a 1.54 ERA with 56 strikeouts in 46 2/3 innings across the two levels.
In 20 appearances with the Royals this season, Coleman has a stingy 0.39 ERA with 24 strikeouts and four walks.
Chris Toman is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.