He played college football for the USC Trojans and was selected by the San Francisco 49ers in the second round of the 2008 NFL draft.

As a redshirt sophomore, he started all 12 games at right offensive guard in the 2006 season, earning a spot on the All-Pacific-10 Conference second-team.

Despite missing three games due to a sprained knee suffered against Washington, Rachal was named to the 2007 All-Pacific-10 Conference First-team Offense.

[2][3] At the end of the season, Rachal's father, Charles, mentioned that his son had told him he was declaring for the 2008 NFL draft due to family medical issues.

[4][5] The month following his father's comment, Rachal stated his 64-year-old father, who works in construction, had recently suffered two hernias, and has tendinitis in his knees and his mother had been diagnosed with an abdominal growth the size of a six-month-old child, though he was unclear whether it was benign or malignant.