Dave Van Horn couldn’t believe it.

At the start of the fall 2021 semester, the Arkansas head baseball coach looked on as a tall, slim left-hander threw his first bullpen session as a Razorback. Still shy of his 18th birthday, the southpaw was one of the youngest players ever to enter Van Horn’s program -- although it was hard to tell that day.

“I was kind of like, ‘Wow, how’s this kid here? Why didn’t somebody sign him [to play professionally]?’” Van Horn recalled. “And thank goodness they didn’t.”

Nearly three years later, Hagen Smith has only gotten better. Unique mental maturity and serious physical growth have propelled the pitcher from an unproven youngster to a bona fide ace, and Smith is on the precipice of his next step. The lefty has been one of college baseball’s premier starters this season, leading to him being selected No. 5 overall by the White Sox in the 2024 MLB Draft -- something that has him excited.

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“I think it’s really cool, man,” Smith said. “I think every kid dreams of doing that.”

Smith’s dreams are coming true thanks to a blend of natural talent, hard work and discipline. Not many people have an electric arm capable of hurling a baseball 100 mph, and those who do typically don’t operate like Smith does.

“He’s not certainly going to be your outgoing, boisterous, loud -- none of that with him,” Arkansas pitching coach Matt Hobbs said. “He comes in and does his work and recovers and sleeps. He’s pretty boring. Most players that are really good are boring, and he’s awesome. Off the field, it’s as buttoned up as it is on the field.”

Asked about his interests away from the diamond, Smith listed relatively few: going to the pool, playing golf, “hanging out with the boys” and spending time with his girlfriend, Katherine, and his golden retriever, Harley.

“He’s got a dog and his girlfriend, and I don’t know that he does a whole lot else,” Hobbs said.

For Smith, that’s just fine. The pitcher would arrive at Arkansas’ facilities as early as anyone, usually by 7:30 or 8 a.m. Smith aims to be in bed by 9 p.m. every night, saying he enjoys getting high-quality sleep and waking up energized.

“He goes about his business like a big leaguer,” Van Horn said. “This isn’t some kid. This is a very mature-thinking person with a lot of talent.”

It’s not a typical college student’s schedule, but over time, it became standard practice for the 20-year-old.

“It’s kind of taken a minute, like a week or two, to get used to,” Smith said. “After that, I feel like an old man, but it’s really nice.”

Smith’s unique work ethic has gotten results. Last summer, when Hobbs went to watch the lefty pitch for the USA Collegiate National Team, the two posed for a picture together. Studying the image later, the Razorbacks’ pitching coach was stunned.

“‘Oh my God. He looks like a man,’” Hobbs recalled thinking. “He looks like a full-grown man all of a sudden.’”

The man Hobbs saw was on a mission. When Smith returned to Arkansas last fall -- with 10 extra pounds of bulk -- he was throwing harder, and his stuff had improved. As a junior, Smith knew he was Draft eligible in 2024, and he knew what a strong year could do for his already-high stock.

“I thought, ‘If I put together a good season, I have a good chance,’” Smith said.

He’s done that and much more. He ranked among the very top pitchers in the country in ERA and strikeouts per nine innings, serving as an invaluable Friday night anchor for the Hogs. On Feb. 23 -- in his second outing of the season -- Smith put it all together, striking out a program record-tying 17 Oregon State batters in six innings at Globe Life Field in Arlington, Texas, and recording every out in the first five innings via strikeout.

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The headline-making performance showed that Smith has come a long way from undergoing Tommy John surgery at age 16 as a Texas high schooler. The lefty injured his elbow the summer after his sophomore year at Bullard High School and missed all of his junior season after his October 2019 procedure.

“Before then, before I got it, I didn’t really know much about pitching, didn’t really know much about training to get my body right,” Smith said. “Going through the rehab process really helped me a lot for the road now -- just doing all the PT, rehab for my arm and stuff and then realizing how big the weight room was for development.”

Former Major League pitcher Robert Ellis, who was Smith’s head coach for his senior year at Bullard, got to see the young pitcher grow firsthand. Not only were Smith’s seven no-hitters as a senior (tying a Texas high school record) notable, but the way the left-hander worked on his game between outings was memorable.

Ellis, who shared a locker room with Hall of Famer Randy Johnson and other star pitchers during his professional career, said Smith’s humility, poise and direction are certainly familiar.

“Everybody’s competitive, but he’s a unicorn,” Ellis said. “I tell people all the time he’s just different. I don’t know how to explain it.”

Smith has already accomplished plenty at Arkansas. On May 16, he broke the Razorbacks career strikeout record. But for Smith, the work is never done.

“He’s put in quite a bit of work,” Hobbs said. “I honestly don’t even think he’s one of those kids that feels like he’s arrived yet, either. I think he probably feels like he’s got more to do.”