For every All-Star, the story of 2019 began on an early morning in Arizona or Florida with a coach.

And the work continued into the regular season, even for the best of them like Brewers outfielder Christian Yelich, who was so displeased with his swing on April 15 that he took his usual drill session out onto the field at Miller Park on a tip from hitting coach Andy Haines. For a full hour, Haines flipped balls into Yelich’s hitting zone. Yelich hit three home runs in a win against the Cardinals that night, part of his franchise-record-setting 31 home runs before the All-Star break.

• All-Star Game presented by Mastercard: Tonight, 6:30 p.m. CT on FOX

Yelich’s big first half won him a spot in the National League’s starting lineup for tonight's All-Star Game presented by Mastercard, one of five Brewers to make the NL squad. Here’s what their coaches, Haines and pitching coach Chris Hook, had to say:

Christian Yelich

Key number: .707, his best-in-MLB slugging percentage.

Haines (also Yelich's manager for three years at the Class A level in Miami’s farm system): “It’s been pretty special to watch. But on a personal level too, when you saw a guy at the very beginning of his career, it’s a special-type feeling watching him now. It’s been a blast. I think what people don’t see behind the scenes is how hard he grinds every day. He makes it seems to easy when the lights come on, but every day he’s very disciplined and takes nothing for granted. He’s willing to try new things every day, which sounds crazy because you’re probably thinking, ‘How risky is that?’ But that’s just who he is. The guy is never going to stay the same. He constantly wants to get better every single day. There’s days we pull our hair out in that cage, and if you watch him when the lights come on, it probably would amaze people to see what he goes through to get to that point in the game where he makes it look so easy.”

Mike Moustakas

Key number: 45, his current home run pace.

Haines: “I think the right word is that last year was kind of a ‘nondescript’ year. I don’t think he had a bad season by any means, but he would be the first to admit that he was capable of way more production. Look what he did in Kansas City, an OPS in the high .800s, 38 home runs. And that’s a pitcher’s park, too. That’s no joke in that park. So he’s just a really talented offensive player. The things we talked about when he signed and got to Spring Training were just getting back to the things he did very well in Kansas City with a little more consistency. Controlling his body a little better. Using the whole field. It’s an elite left-handed swing. He’s been an elite hitter since high school if you go back. It’s him getting back to what he is. With the year Yelich is having, we probably don’t talk about it enough.”

Yasmani Grandal

Key number: 21, Dave Nilsson’s franchise record for home runs as a catcher. Grandal has hit 18 of his first 19 homers this season as a catcher.

Haines: “Switch-hitters always tend to be a little more maintenance. I always say they’re like two different people. There’s Yasmani the right-handed hitter and Yasmani the left-handed hitter, and I think he’s benefited from playing every day and he’s taking advantage of that. If you look all the way back to early day ... he was a really productive right-handed hitter back in San Diego and the Minor Leagues. He had high hands, he had a big leg kick. And then he kind of got away from that in L.A., probably from not playing a lot [against lefties]. So that was something we spent a lot of time on in Spring Training. We knew he was capable of way more right-handed.”

Josh Hader

Key number: 51 percent, Hader’s strikeout rate. Aroldis Chapman set the all-time record (minimum 30 innings) at 52.5 percent in 2014.

Hook: “He’s just so no-nonsense and such a competitor when he comes out and gets on the mound. I think he’s always been that way since we got him, and he continues to do it. Regardless of what level he’s been at, he’s always been that. There’s not a lot of sequencing to talk about with him, obviously, but there are some delivery things we keep tabs on with him and periodically touch on. The arm slot, the action, the velocity. There’s just not too many people who do that. It’s different. There’s not too many like him.”

Brandon Woodruff

Key number: 100 mph, the velocity of Woodruff’s firmest fastball this season. It was the first time since Statcast started tracking in 2015 that a Brewers starter touched triple digits.

Hook: “I think there’s been a lot of growth in the last three years. Getting up in ’17, to last year, and then to this year, there have been leaps and bounds in terms of things like what he’s doing with runners in scoring position, his thought process, his consistency. I’ve got such a history with some of these guys, so I get to see the changes in maturity from where they were to where they are now, and to see him pitching at a very high level is very rewarding for a coach. Delivery-wise, I think right now, his delivery is in a really smooth state. I remember when we were in [Double-A] Biloxi in 2016, he sped it up, and once we sped it up, he smoothed it out. Last year, at the end of the year when he got in the playoffs, it started clicking for him, and this year it’s been that way from the beginning. I’m just excited for him. There’s still another step in there.”