MESA, Ariz. - David Ross first saw Yu Darvish up close on May 5, 2013, when the light-hitting Red Sox catcher homered off the once-stoic Rangers pitcher.
More than five years later, Ross noticed a change in Darvish, now with the Cubs, from team President Theo Epstein's suite at Wrigley Field.
After Darvish struck out the Reds' Yasiel Puig to end the inning, Ross watched in amazement as Darvish pumped his fist before yelling in the direction of the Wrigley Field bleachers.
"I almost came out of my seat," the Cubs manager said. "That was the first time I'd seen emotion from him."
The emotional release represented the transformation of a successful and personal turnaround for the Japanese pitcher.
No longer does the 6-foot-5 Darvish scoot past reporters through the clubhouse like a running back eluding tacklers, as he did during his injury-plagued first season with the Cubs in 2018.
He occasionally displays a colorful sense of humor to reporters, and he enjoys the banter with followers on his social media accounts.
"I'm always fighting with some guys (from Japan)," Darvish said of his frequent exchanges on Twitter. "I don't care."
The response to his YouTube channel is more favorable.
"Usually I talk about baseball, Japanese culture and what's going on here," Darvish said. "And people like it."
Darvish's reputation took a hit after the 2017 World Series as a member of the Dodgers, and his statements about the Astros sign-stealing scandal have become stronger to the point he advocated stripping the Astros of the title.
After some Astros fans fired back on Twitter, Darvish trolled them by responding to a photo of the 2017 World Series trophy with the comment, "Gorgeous trashcan! I like it!"
Most encouraging to the Cubs, however, is the dominant pitching he displayed during the second half of 2019 that eased concerns he wouldn't live up to his six-year, $126 million contract.
Darvish's fist pump and scream against the Reds put the exclamation mark on his first win at Wrigley as a member of the Cubs after 13 home starts. Darvish posted a 2.95 ERA in his last 14 starts, striking out 39 in his last three starts and becoming the first pitcher in franchise history to strike out at least 12 in three consecutive starts.
"(The fist pump) told me a lot about where he was with his confidence," said Ross, who spent the last three seasons as a Cubs special assistant.
"I didn't have any true opinions on him, to be honest with you. Just I love watching his stuff. That slider is nasty. If I had an opinion on him, every time he throws his slider, he's nasty."
Darvish, 33, has taken measures to preserve his arm after a series of injuries. He underwent Tommy John surgery in 2015 and had right triceps tendinitis and a stress reaction in his elbow that limited him to eight starts in 2018.
"Throwing hard feels much different than last year," said Darvish, who said he has lingering concerns about his elbow.
Darvish skipped a long-toss session last weekend, and there will be preventive measures similar to the final three months of 2019 that enabled him to finish strong and build trust between him and pitching coach Tommy Hottovy.
"We were aware that he threw only 40 innings (in 2018), so we tried to find those times (for rest)," Hottovy said. "He's so good with the awareness of his body and how he feels. He'll say: 'I'm getting a little gassed right now. This is the time to back off.'"
One of those occasions occurred midseason when he received six days of rest before his final start of the first half and an eight-day break prior to his first start after the All-Star break.
Darvish skipped a start in early September because of forearm discomfort but responded with his most dominant stretch to finish the season.
"It was the right time to turn it up a notch," Hottovy said.
The Cubs must find a way to achieve balance, but Darvish is adamant about retaining his control. After walking 49 in 97 innings in the first half, Darvish issued only seven walks in 81 2/3 innings the rest of the way to finish the season with a 4.09 strikeout-to-walk ratio.
That prompted Darvish to resume playing catch in November and retain the same control in early bullpen sessions.
"I was just so scared to lose the feeling, so I started earlier than usual," he said.
Despite the occasional breaks, Darvish has set high goals: He wants to start 33 to 34 games and pitch more than 200 innings this season, numbers that would approach his career highs of 32 starts and 209 2/3 innings in 2013 - when he led the majors with 277 strikeouts.
His recent success, however, hasn't changed Darvish's meticulous approach, whether he's training or taking extra time between pitches during a bullpen session to study his results tracked by a Rapsodo machine.
"I still overanalyze and like doing that," Darvish said.