But Soler, whom the Royals acquired from the Cubs for fan favorite and closer Wade Davis, has been tantalizingly good so far in 2018. Following Monday's 10-6 loss to the Red Sox, Soler was hitting .304 with two home runs and six RBIs and a team-leading .434 on-base percentage.
"I'm very intrigued by him," Royals manager Ned Yost said. "Last year was such a struggle up here for him. But we sent him down [to Triple-A Omaha] and he put up really good numbers [with 24 home runs and a .952 OPS].
"I knew if we could just get him consistent at-bats up here he would do OK."
What has been most impressive to Yost and his coaching staff is Soler's plate discipline. Soler has drawn a team-high 18 walks, and entering Monday's game, he had seen 4.46 pitches per plate appearance, fourth best in the American League. Matt Davidson of the White Sox has seen the most at 4.56.
"He's not chasing much of anything," Yost said. "Occasionally he'll chase a bad pitch, but not consistently."
The plate discipline is by design. Soler said that he is watching more video of opponents and is focused on going after hitters' pitches only.
"I'm very proud of that," Soler said through interpreter and coach Pedro Grifol. "Almost every at-bat, I'm 1-2, 2-2. I'm prideful to extend ABs. Thanks to Pedro, too, who's helped me a lot, scouting pitchers before the game. I kind of know what the pitcher is going to do with me, which isn't something I did before."
Grifol paused for a minute, then said, "I can vouch for that. He's putting in the work. Not so much the physical work, but he's putting in the mental preparation that is necessary."
Of course, there are still issues with Soler defensively. He has dropped two routine fly balls already this season, and taken bad routes on others. But he did make a four-star catch, according to Statcast™, on Sunday.
"I know he's a work in progress in the outfield," Yost said, "but he's gotten so much better from last year. He's going to make mistakes out there, but he'll learn from it. And he's going to keep working."
Soler vows he will improve, too.
"I feel like I've gotten better in the field," Soler said. "I'm more on-time with jumps on the ball."
For now, Yost is simply enjoying watching the development.
"Pretty amazing to watch him," Yost said. "I was always amazed watching Carlos Santana. He would walk 100 times a year. He'd hit .220, but he'd always have a .380 or .390 on-base percentage. Adam Dunn was like that. But [Soler] looks like the complete package. A lot of walks, good average with power."