PROVO, Utah -- The question was filling up Twitter timelines, driving message board banter, prompting press box dialogue -- why aren't the Trojans using Markese Stepp?

On a day where BYU got USC's passing game totally out of sync and forced the Trojans to lean on the ground attack, they did so while largely ignoring the potential that their most effective rusher might have been the one standing on the sidelines for most of the first three quarters.

Redshirt freshman running back Markese Stepp's usage has been a flashpoint of frustration for fans all season -- after he was not used in the opener and played just four snaps late in the win over Stanford. This time, he did actually get in the game earlier, and he provided an immediate boost -- with USC down a touchdown midway through the second quarter, he seized his first opportunities while breaking off runs of 12, 6 and 15 yards on his first three touches.

Just like that he wasn't heard from again until the start of the fourth quarter, as the running game was all the while too often stalling with veterans Vavae Malepeai and Stephen Carr.

Stepp would get 6 of his 9 carries in the final quarter (none in overtime), converting a third-and-1 and two fourth-and-1s. Despite essentially being used as a short-yardage back, he still led the team with 5.9 yards per carry in totaling 53 yards.

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His physical, bruising style and penchant for consistent yards after contact are indeed useful in short-yardage situations, but they also would have been useful when USC turned to the ground game in the third quarter and went three-and-out (two runs by Carr for net 0 yards) and punted again after four consecutive runs by Malepeai (a nice 16-yard gain followed by diminishing returns of 4, 3 and 2 yards).

Coach Clay Helton was asked after the game why the staff didn't go back to Stepp sooner.