CHICAGO -- By now you know what Chicago Cubs manager Joe Maddon says to leadoff man Dexter Fowler before every game.

"You go. We go."

Over the first month of the season, that saying couldn’t be more accurate. Fowler hasn’t stopped "going" since Opening Day, compiling video-game-like numbers with a .506 on-base percentage, a 1.198 OPS and 215 OPS+ -- second best in the National League this season. For perspective, the league average OPS+ is always 100.

Fowler’s team is 14-5 as it begins a homestand Tuesday against the Milwaukee Brewers. And it’s no coincidence the success of the team and the player go hand in hand.

"He stays within himself," Fowler's teammate and good friend Jason Heyward said over the weekend. "Doesn’t try to do too much. He’s aggressive in the strike zone and uses all of his tools. He takes advantage of the lineup around us."

That’s the technical breakdown. Veteran David Ross put it more succinctly.

"He’s our MVP," Ross said. "No question about it. Maybe of the league so far."

That’s high praise considering first baseman Anthony Rizzo is among the league leaders in home runs and RBIs, and starter Jake Arrieta is 4-0 and just threw a no-hitter.

The common thinking regarding Fowler is that he’s playing with a chip on his shoulder after being spurned in free agency this past winter. It’s well documented how he famously returned to the Cubs at the last minute, taking less money for one year than the team originally extended to him via the qualifying offer back in November. And he never found a multiyear deal from another team to his liking despite a monster second half last year.

But the chip-on-the shoulder reasoning doesn’t do service to how hard Fowler worked this offseason. He shed what little body fat he had while putting on close to 20 pounds of muscle. It’s made a world of difference -- especially batting left-handed, which has traditionally been his weaker side.

"From a technical perspective, his left-handed swing is better," Maddon said. "He’s not drifting as much to the ball. His swing is under control. He’s not chasing as much from that side.

"I see strength being different. Maybe balance. Beyond that, I think he’s made some mechanical and physical adjustments as well."

Hitting coach John Mallee added: "He’s gotten into a better position of using his legs, especially left-handed. He’s really improved."

Fowler can explain it himself, as his keen eye at the plate combined with hard contact when he does swing has made him as dangerous as anyone in the Cubs' lineup.

'I’m seeing the ball like I normally see it,' Fowler said. "I think my mechanics are a lot better. My balance is a lot better. I put on weight, so that’s definitely helping.

"I’m stronger and more balanced. I don’t have to do too much. See the ball, hit the ball."

The physical transformation took place in a gym in Las Vegas, where Fowler spent the winter. His work at the plate came in the solitude of Kris Bryant's hitting cage at his parents’ house in a Las Vegas suburb.

Maybe Fowler deserved Jacoby Ellsbury-type money (seven years, $153 million), but when those offers never arrived, he wasn’t going to let it get to him -- or at least he wasn't going to show it.

"I probably would have felt that way [upset]," Maddon said. "He’s such a nice person, he probably doesn’t want to go there. But if you ask me, I probably would have had a chip."

Added Ross: "Dex doesn’t seem like that guy. He’s more of a positive, fun kind of guy. You can definitely tell he’s locked in.

"I’m just glad he’s carrying the rest of us, because when the ship gets going and he’s doing that, it’s going to get ugly."

It’s ugly now, as the Cubs lead the majors in run differential by a wide margin and Fowler is tied for the NL lead in runs scored.

"We’re all on a mission, to be honest with you," Heyward stated. "He has some good guys behind him in the lineup. I know how that feels. It’s a good feeling. I benefit from it.

"I don’t sense a chip. I think he’s comfortable. I think he has a sense of urgency."

It’s easy to assume the urgency comes from another shot at free agency again this winter, but that’s not what anyone close to Fowler says. They believe he’s simply happy in Chicago. Remember, he could have signed with Baltimore or another team for more than the one-year, $13 million deal he took with the Cubs, but he stayed with the team he loves and that loves him back.

"I was definitely surprised," Ross said of the lack of big offers. "And when you play with a guy, you do get a greater appreciation for his talent. He was, and is, the catalyst for this team. I can’t imagine us without him and his smile around."

Neither could Maddon, who said in spring training he "didn’t know we knew how important that piece was until it actually came back to us."

And now that piece to the Cubs' puzzle is challenging for player of the month for April. He might smile a lot and be happier than ever to be back in Chicago, but nothing motivates a player like being disrespected. The Cubs are the beneficiaries of whatever is actually motivating their center fielder.

"You try to find a way to motivate yourself," Ross said. "If that’s the way he does do it, that’s great. As long as it’s channeled the right way. I’m just happy he’s off to a great start."

When asked over the weekend, yet again, about the proverbial chip, Fowler gave the same answer he’s been giving since he surprised everyone at Cubs camp in February -- and he did it with his usual smile.

"I always put a chip on my shoulder," Fowler said. "There’s always something to prove."