Gio Gonzalez, shown at spring training with catcher Wilson Ramos, left, might be a goofball. But his jovial personality masks a strong work ethic and determination on the field. (Alex Brandon/Associated Press)

Gio Gonzalez found a picture of Steve McCatty, his pitching coach and his foil, placed in his locker Wednesday morning. McCatty was sitting on a stool wearing glasses, sliding shorts and an ice wrap on his knee. Gonzalez taped the photograph to the sliver of wall next to his stall. “It’s my conscience,” he said.

Gonzalez bounded to every corner of the Washington Nationals’ clubhouse. He leaned over to show Stephen Strasburg something on his phone, which drew laughter from the ace. He walked over to the catchers and spoke Spanish with Wilson Ramos, Jose Lobaton and Jhonatan Solano. Gonzalez spotted lefty reliever Jerry Blevins, once his teammate with the Oakland A’s, and shouted, “Hey, Jerr Bear!”

At least the whole team was not laughing at him. Two mornings prior, a video screen had been erected at one end of the clubhouse for the purpose of projecting an image of Gonzalez, taken from his Instagram feed, posing like a model. Mention “Gio’s hashtags,” and everyone in the Nationals’ clubhouse knows what you mean.

The familiar, goofball persona explains why fellow pitchers enjoy playing with Gonzalez. It does not explain how Gonzalez, at 28 and entering his third season with the Nationals, has become one of the best left-handed starters in baseball. In his first week observing Gonzalez, the team’s new manager has noticed what happens when Gonzalez steps to the mound. The chatterbox becomes quiet.

“It’s interesting because Gio is very outgoing as we all know and very happy-go-lucky,” Matt Williams said. “But I also know that when it’s time for business, he’s ready to go. He’s about pitching.”

Gonzalez’s loose nature has not changed since he first entered the league. “Same guy,” Blevins said. “Better cars.”

It also can mask the work ethic he maintains. Gonzalez dedicates himself to offseason workouts, waking up early at his home in Hialeah, Fla., a few hours south of Viera. He has grown stronger and smarter.

“He’s gotten better,” Blevins said. “As you get older, you can’t help but adapt and learn or you’re going to get passed up by other guys. Gio, he’s done that. He’s got better command. He understands the game plan a little bit better. I’m excited to see him during the season, see how he’s grown. He’s always had a good work ethic. He just works smarter now. He knows what he’s doing, how he’s going about things.”

Based on his outward demeanor, Gonzalez would never be taken as a player to apply too much pressure. But his internal drive led to frustration last season. Every year of his career, Gonzalez had always improved. After he went 21-8 with a 2.89 ERA and finished third in the Cy Young vote, he assumed he would take another leap forward in 2013.

“You always want to get better,” Gonzalez said. “You always want to do something you couldn’t do. You want to win 30 games. You want to go perfect. But sometimes you have to be realistic.”

Gonzalez pitched well enough last season, but another solid year only frustrated him. His ERA rose to 3.36, his highest since 2009, and he won 11 games. He screamed into his glove during starts and stomped between the mound and the dugout. His focus sometimes waned — when he forgot to cover first base late in the season, it led to a shouting match with Jayson Werth.

This offseason, Gonzalez had to do something no one would have imagined. He reminded himself to enjoy himself on the mound, not to let pressure or expectations sap his joy.

“You want to stay at that pace where you can just have fun,” Gonzalez said. “Don’t worry about the numbers. The numbers are going to speak for themselves. But you as a person, just stay healthy and stay strong. You want to always try to match or do better, and that’s something you can’t do. You live and you learn. You get older. You get wiser. You realize, stop thinking like that. Stop putting pressure on yourself. Just pitch.”

Even after a year that left him unsatisfied, the Nationals have a tremendous value in Gonzalez, an all-star caliber pitcher who has been worth about four wins above replacement per season over the last three years. He will not turn 29 until September, which means he still has several prime seasons left. And if the Nationals want, they have him under contract for the next five years at the bargain price of $55.5 million — but only three guaranteed years for $32 million.

As Gonzalez has stayed healthy and consistent, his contract has become a boon for the Nationals. In what would have been the final two years of arbitration eligibility, Gonzalez will make $19.5 million. Over the same span, at the same point in his career, Jordan Zimmermann will make $24 million.

Unlike Gonzalez, Zimmermann then will have the opportunity to test free agency. In what would have been his first three free agent seasons, from 2016 through 2018, Gonzalez will make $36 million over three years — $6 million more than what Scott Feldman signed for this winter.

And it actually gets more favorable for the Nationals. If Gonzalez suffers a significant setback in performance or health in the next three seasons, they can choose not to exercise $12 million options in 2017 and 2018. If things go right, the Nationals get an ace at a No. 3 or 4 starter price. If things go wrong, they have little exposure.

During these days of spring training, none of that enters Gonzalez’s mind. He wants to continue having his fun off the mound and focus on having more fun on it, too.

“It’s more going back to just having fun,” Gonzalez said. “I just want to go out there and let these guys know I’m ready to go, ready to rock and roll. Bring on 2014 and see what happens. I want to keep learning. I want to keep stronger, mentally, physically, letting these guys know I’m not playing around this year. It’s going to be more, get my job done and then have fun after.”