Quinn, the league's top-rated quarterback, injured an ankle last week, opening the door for Arellanes.
Harbaugh, the league's top-rated quarterback, was 12 of 18 for 180 yards.
Bomar went to Oklahoma three years ago as the top-rated quarterback recruit in the nation.
Kurt Warner of St. Louis is the top-rated quarterback in the league.
The six top-rated quarterbacks in the league are at least age 32 and have played at least nine pro seasons.
He was the top-rated quarterback in the Midwest in 1993.
Kerry Collins, the nation's top-rated quarterback, completed 19 of 23 passes for 265 yards and 2 touchdowns.
On first down, Kelly, who began the day as the American Conference's top-rated quarterback, threw a short pass to the right side.
Moore ended his senior season as one of the top-rated quarterbacks in the nation.
He has suffered from elbow problems, while Young has become the league's top-rated quarterback.