He played college football for Rice University and thereafter was selected by the Cincinnati Bengals in the fourth round of the 1991 NFL draft.
He participated in training camp with the Detroit Lions and Houston Oilers in 1995 and 1996 and spent the 1997 off-season with the Washington Redskins before making the roster of the Oakland Raiders later that year.
Oakland was on a two-game winning streak when Hollas took over the 3–2 Raiders starting job, after helping them to a 23–20 victory over Arizona the week before with a touchdown run.
Then, he promptly led the Raiders to three more victories in a row for a five-game winning streak and a 6–2 record at the halfway point under first-year head coach Jon Gruden.
He was the head football coach and associate athletic director at St. Thomas High School in Houston, Texas from May 2008 through January 2012.