MARION - Part of an invisible business, Southern Illinois Miners assistant coach Ron Biga says as much as anyone just by being at Rent One Park today.

In charge of scouting future Miners opponents in the Chicago area, Biga, 41, also serves as manager Mike Pinto's No. 1 sounding board for evaluating players in Marion. Between Monday and Friday most weeks, he has to do it from afar, as he works 50 hours a week for Prairie Materials, a company that sells concrete to independent contractors in the Windy City. The rest of the week he's either on the phone with Pinto, at Windy City's Standard Bank Stadium, in Rockford, watching a game two hours away in Kalamazoo, Mich., or with the Miners.

"If I need a guy, he has a comparison to the guys we have," Pinto said. "He's here during spring training. He sees what guys' work ethics are, how guys go about what they do. He's a guy that I really bounce a lot of player ideas off of."

Tuesday, he returned to Chicago at 3:30 in the morning from the Miners' game at River City, worked at his day job from 7 a.m. to 4 p.m. and went to Windy City that night. Growing up in Chicago, he traveled an hour and a half each way to go to St. Rita High School. He grew up poor, eating M&Ms for dinner some nights and living without electricity other evenings. Outside of baseball, he cleaned locker rooms, washed uniforms and did anything at St. Rita to pay for his tuition.

The left-handed pitcher "way beyond his years" soon saw baseball pay him back.

A high school All-American, he was selected to play on the U.S. Junior National Team in the late 1980s and went to Taiwan, Venezuela, Holland and Spain. Biga pitched for Murray State coach Rob McDonald shortly afterwards, when McDonald was the head coach at Lincoln College.

"He was 45-4, or something like that, in high school," said McDonald, a friend of Biga's for the last 24 years. "I always thought he was like a 19-year-old going on 29. He was so far advanced beyond the other kids. His age, mentally and mechanically. He just was way far advanced beyond his years."

After his playing days were over, he turned to coaching. He started running a semipro team in Chicago called Prairie Gravel in 1992, and stayed for more than a decade, winning the NBC World Series in 2005. Watching some of his players sign professional contracts only added to his affection for the game. More than 100 of his former players have signed professionally, including Detroit Tigers center fielder Curtis Granderson.

"You have to have a passion for it. You're never going to get rich doing it, and the thing is, you see good rewards," Biga said. "You make friends for life. And you see guys sign their first professional contracts, that's their dream. And as you get older, you remember these things."

If the Miners advance to the playoffs, they might credit Biga's advance scouting for some of the success. Southern Illinois (23-16), entered Friday's game against Evansville 3 1/2 games back of River City in the Frontier League's West Division. First baseman Brad Miller was leading the league with 41 RBIs, pitcher Ryan Bird was 6-0 with a league-best 1.62 ERA, and the Miners had the fifth-best team ERA in the league.

If the Miners don't match last year's playoff run, Biga will likely keep the same schedule. He is, unquestionably, a baseball guy.

"He's a baseball guy," McDonald said. "He thrives on that, and if he was ever in a position where he was only doing baseball, think of the energy he'd have for that."

todd.hefferman@thesouthern.com / 618-351-5087