Soler, who is out of options, was touted as a five-tool player when the Cubs signed him in 2012. The Royals, in turn, thought so much of his potential that they traded closer Wade Davis for him during the 2016 Winter Meetings.
Now the Royals are eager to see those tools on display for an entire season.
"We need for him to get 500-600 at-bats," Royals manager Ned Yost said. "We need to know and find out what we have there. You can see the talent."
Soler certainly has shown flashes of that talent this spring. He entered Friday tied for the Cactus League lead in home runs with six, and leading the Royals in walks with eight.
"You can tell he has a good eye at the plate," Yost said. "His ability to draw walks will keep his on-base percentage up even when he might be in a slump. That's what good hitters are able to do. And, of course, he's got that raw power."
Yost envisions Soler as a potential 30-40 home run hitter. Injuries slowed Soler's 2017 season, yet he hit 24 home runs at Triple-A Omaha.
Yost also has been impressed with Soler's defense at the corner-outfield positions.
"His routes are better, he's taking better angles," Yost said.
Soler did his part to prep for a breakthrough season, losing 19 pounds over the winter.
"I just feel better and am moving around better," Soler said through an interpreter. "It has made a difference."
The Royals' coaching staff has taken notice. Third-base coach Mike Jirschele remarked recently, "Just seeing him go from first to third on a single to center was pretty impressive. He can run."
Gordon's performance in 2018 also will be under the spotlight.
Gordon's elite defense -- he won his fifth Gold Glove in 2017 -- has kept him on the field. But after dreadful offensive seasons in '16 (.220) and '17 (.208), Gordon also has struggled this spring (.118).
Yost even suggested to Gordon that he spend some time in Minor League games this week -- a common practice for veterans during Spring Training that allows them to get 12-14 at-bats per day. Gordon did so Thursday, but he only had four at-bats, Yost said. Gordon started in left field for the club's split-squad matchup with the Dodgers on Friday afternoon.
"His timing is just off," Yost said. "But he'll figure it out. He always does."
But what if Gordon's offense doesn't pick up when the regular season starts? Can the Royals live with another season from an elite defender who doesn't produce offensively? Or would the Royals sit a player such as Gordon, who is owed $40 million over the next two years?
The Royals can't answer those hypothetical questions now, but they may have to down the road.