PHILADELPHIA — Two days shy of the anniversary of being drafted by the Chicago Cubs made Sunday’s appearance in the All-Star Futures Game a surreal experience for Josiah Hartshorn.
When the Cubs selected Hartshorn in the 2025 sixth round, ultimately going way over slot at $2 million to sway him from going the college route, the organization envisioned big things for the first baseman/outfielder who only turned 19 in February. Now, 363 days after getting the call that he was drafted on July 14, Hartshorn shared the field at Citizens Bank Park with some of the top prospects in baseball.
“Coming to a big-league ballpark, especially in All-Star week, is something special,” Hartshorn told the Tribune. “Even the traffic getting into the hotel Saturday was unbelievable. But this is such a blessing.”
Hartshorn and right-hander Mason McGwire represented the Cubs in Sunday’s Futures Game, each seeing action in the National League’s 6-1 loss to the American League. Hartshorn entered in the top of the fourth and went 0-for-2 with a groundout and a flyout. McGwire saw action in the final inning, hitting one batter and recording a strikeout.
Hartshorn, rated the No. 29 prospect in the minors by Baseball America, has crushed the ball in his first professional season. He needed only 39 games to prove to the Cubs he was ready for a tougher challenge, regardless of his age and experience, behind a disciplined approach that saw him record more walks than strikeouts at Single-A Myrtle Beach. Hartshorn’s power was on immediate display with High-A South Bend, where he’s slugged 10 home runs, five doubles and two triples with a .279/.371/.544 slash line in 40 games.
“Something I’ve been pretty proud of is being consistent,” Hartshorn said. “I mean, it’s been a little bit of a struggle recently, but just staying consistent, not really riding the wave of the season. Obviously, it’s a long season. This is the most baseball I’ve ever played, but being consistent day in and day out and taking care of what I need to do off the field to be able to stay on the field and be healthy, I think I’ve done a good job of that, and I’m pretty happy with that.”
Hartshorn’s and McGwire’s journeys to the Futures Game followed a similar path, each opening the season at Myrtle Beach and now with South Bend — and also as roommates at both affiliates.
“I’ve never seen him play, and I didn’t really know anything about him, he’s got a great approach at the plate,” McGwire said of Hartshorn to the Tribune. “He’s never out of it, and he’s always battling. It’s great to see.”
McGwire, the Cubs’ No. 29 prospect according to MLB Pipeline, missed all of 2025 due to a partial tear in his elbow. Although the 22-year-old avoided surgery that could have caused him to be out for part of this season, too, he missed important development on the mound. McGwire tried to find ways to stay disciplined and keep improving every day as his patience was tested. He came into this year with one main goal: to stay healthy.
“But also not letting health limit my performance,” McGwire added. “Leave it all out on the field, not letting risk of injury limit my performance.”
Through 16 games (10 starts) between Myrtle Beach and South Bend, McGwire owns a 2.94 ERA with 20 walks and 67 strikeouts in 52 innings. It all comes back to fastball command for the Cubs’ eighth-round draft pick in 2022. If his fastball command is locked in early, he knows it’s going to be a good day on the mound.
Standing in the home clubhouse at Citizens Bank Park wasn’t an unfamiliar feeling for McGwire. He spent a lot of time in big-league clubhouses as a kid when his father, legendary slugger Mark McGwire, was a hitting coach for the St. Louis Cardinals (2010-12) and Los Angeles Dodgers (2013-15), and bench coach for the San Diego Padres (2016-18).
Mason McGwire, who was born in 2004, remembers always being around a major-league clubhouse with his brother during summers those years, saying, “We basically grew up in the clubhouse.” It taught him a lot about a professional baseball environment and what he could experience in the coming years.
“The way guys go about their business, how they handle themselves, like, even the funny guys on the team, there’s just different ways to go about it,” McGwire said. “There isn’t one way. A professional approach, but you can still be yourself. You can still be you.”
Gaining the perspective of a successful big-league hitter has been valuable during his own pro career. McGwire appreciates how his dad picks up on things a lot of other people don’t, like if his arm slot changes, and offers advice on how his pitches play off each other.
“And the intimidation factor — mound presence,” McGwire said. “Things that you can’t really measure how important they are.”
So, how would McGwire match up against his dad in his prime?
“I think I could compete,” he countered.
In the winning clubhouse Sunday afternoon, White Sox prospect Caleb Bonemer couldn’t stop grinning.
Bonemer, ranked the Sox’s top prospect by MLB Pipeline, started at third base, going 0-for-2 and handling the lone ball hit his way. He made sure to take in the atmosphere. Although Bonemer played in big-league stadiums during summer ball in high school, he had never experienced one with so many fans in the stands.
“It kind of felt like I was playing a video game almost,” Bonemer said. “Just a great environment. I mean, it’s what you dream of, playing in front of a lot of people like that. I felt great out there and really enjoyed it.”
After he finished his last round of pregame batting practice, former big-leaguer Kenny Lofton approached Bonemer and told him he liked his swing, “so keep doing what you’re doing.” The interaction added to a memorable day for the Sox’s 2024 second-round draft pick.
As he heads back to Double-A Birmingham, Bonemer’s major-league goals feel a little closer.
“All those arms that we saw today were big-league caliber stuff and I felt comfortable in the box, I feel like I saw it pretty decent, so that’s a good feeling to have,” Bonemer said. “I just try to take it a day at a time. Whatever they’ve got for me is good with me. But, yeah, obviously if I play well, that’ll happen. So I just try to focus on that. But playing in an environment like today, yeah, it was a pretty cool moment. You dream about stuff like that.”
