INDIANAPOLIS -- Chilo Rachal was a big man poised to become an even bigger man on the USC campus.
He was penciled in next season as a third-year starter at right guard, a possible candidate for All-American honors, and figured to be one of the more coveted offensive linemen in the 2009 NFL draft.
Instead, Rachal decided to forgo his senior season to enter the draft a year early, and now is the only underclassman among 12 Trojans at the scouting combine.
In his first public comments since choosing to leave school early, Rachal said Thursday, "I had to do what was best for my family."
Rachal said his 64-year-old father works construction, recently suffered two hernias, and has tendinitis in his knees.
He said his mother has been diagnosed with an abdominal growth the size of a six-month-old child, although Rachal was unclear whether it was benign or malignant.
Asked if she has been hospitalized, he said: "No, she's been getting a lot of treatment. It hasn't gotten that severe to the point where she needs to be in the hospital yet."
Rachal said his mother told him of her health problems after the Trojans played UCLA in early December.
"My mother didn't want to tell me during the season because she thought that it would take me off my game," he said. "So she waited until toward the end of the season to tell me. Once I realized that, I figured I had to do what was best for us."
Unlike teammates such as Sedrick Ellis, Keith Rivers and Lawrence Jackson, all of whom boosted their draft status by staying at USC for their senior seasons, Rachal is following a path similar to that of Fred Matua, the former Trojans guard who cited his mother's illness as his reason for leaving school as a junior after the 2005 season.
After being drafted in the seventh round and later waived by Detroit, Matua has bounced around as a little-used reserve on active rosters and practice squads.
Rachal is generally thought to be among the top 10 guard prospects in a draft loaded with talented offensive linemen. Experts predict he will be selected somewhere between the third and sixth rounds, meaning he stands to earn considerably less on a rookie contract than elite guard prospects such as Branden Albert of Virginia and Roy Schuening of Oregon State.
Ranked just ahead of Rachal by many scouts is fellow USC guard Drew Radovich, who said he supports his teammate's decision to leave early.
"Family comes first," Radovich said.
Rachal had minimal contact with his USC teammates and coaches in the week following the Trojans' Rose Bowl victory over Illinois.
USC Coach Pete Carroll said he will be rooting for Rachal in the draft but he would have liked to have counseled him before Rachal made his decision.
"I think it was a classic approach of a guy who had it in his mind what he was going to do. . . . " Carroll said. "They only talk to people that agree with them so it's not much of a decision."
Last week, Carroll praised the decision of the 11 seniors who opted to stay in school.
"It's a one-shot deal getting drafted," he said. "And that's why we're so adamant about guys, when it fits their situation, to stay in school and capitalize on the next year's development, show how they can make tremendous improvement in their value in that next year."
After Rachal submitted his early-entry paperwork last month, his father described their phone conversation.
"He said, 'Daddy, I made up my mind. I want to go pro,' " Charles Rachal said. "I told him, 'If that's what you want to do, I'm not going to stand in your way.' "
Rachal, who spent four years at the school because of his redshirt freshman season, said he is one semester away from graduating with a degree in sociology and intends to complete that.
"It was real difficult," he said of the choice to leave. "I had to sit there and think about it, think about the pros and cons of it, and then I pretty much made the right decision."
Times staff writer Gary Klein also contributed to this report.