As a member of the Cubs' Class A Daytona team last April 10, he ran across the field toward the Clearwater Threshers' dugout in a Florida State League game. It came moments after words were exchanged regarding contact at second base on a slide by Soler.
And Soler had a bat in his hand.
"You have to respect baseball and my teammates," Soler said through a translator Wednesday morning from spring training. "It was a big mistake that I made. But I learned from it."
He never swung the bat at anyone, but the incident made headlines and got him suspended for five games. It also created doubts about his character after the Cubs signed him to a nine-year, $30 million deal the previous summer.
"He wasn't used to the game in the USA," friend and teammate at the time Javier Baez said. "It's completely different. Everything is a fight in Latin America. We argue more."
The front office told Soler that he needed to calm down; indications are he has. New Cubs manager Rick Renteria has a different impression of Soler than the one he earned that day.
"Very calm," Renteria said. "It doesn't look like pressure affects him very much."
When reminded of the April incident, Renteria preferred to look ahead.
"From what I've seen, he's very composed," Renteria said.
But after returning from the suspension, Soler suffered a stress fracture in his left leg that ended his season prematurely in late June. First a suspension, then an injury. In between, he hit .281 with a .343 on-base percentage to go along with eight home runs and 35 RBIs in just 55 games. But his season was over.
"It was a rough year," Soler said. "But I'm working hard to be better. I'm in good shape. I've been running a lot. I have no soreness or anything. Everything is 100 percent."
After getting healthy, it didn't get any better for him in October and November when scouts said he was lazy during Arizona Fall League play. But the Cubs insist they told him to take it easy coming back from the injury and explained he wasn't in game shape because of inactivity. He made the all-star team anyway.
Still, the hype surrounding him has seemingly been bypassed for players such as Baez and 2013 No. 2 overall pick Kris Bryant.
"I'm working every day on my hitting skills and getting better," Soler said. "Leaving the bat in the strike zone a little bit longer."
Soler wouldn't be the first player to lose some of his hunger and love for the game because he's earning a fat paycheck, but he insists that's not the case.
"I don't think about the contract when I'm going to play," Soler said. "I'm still hungry and want to help the team."
He can do that with what Renteria calls a "very high skill set." At 6-foot-4, 215 pounds, Soler looks the part of a great athlete. His five-tool ability is the reason the Cubs signed him to such a lucrative deal at such a young age. He turned 22 on Tuesday, so maybe the maturity will come.
"He just needs to get used to being here," Baez said. "He'll be fine."
Renteria compared Soler's "physicality" and athleticism to Ken Griffey Jr. at the same age, although was quick to leave the comparison there.
As for Soler, he's working on his swing in camp -- he wants to keep the bat through the hitting zone a fraction longer -- and he wants to put the bat incident behind him. He'll start the season at Double-A Tennessee.
"I just have to calm down," he said. "That can never happen again."