Lane Kiffin has said that the big thing missing from the USC offense right now are explosive plays in the run game. The passing game has been able to provide plenty of big plays and Marc Tyler has been a steady presence on the ground, but outside of one 43-yard run from Curtis McNeal against Syracuse there really haven't been any big gains from the running attack.
During spring ball and fall camp it looked like D.J. Morgan was going to provide that element, but some early fumbles have made Kiffin hesitant to count on him right now. Amir Carlisle offers a speed option and he was used in the ASU game, so he certainly could see an increased role. The move of George Farmer to tailback, however, is a clear sign of how much Kiffin is looking to find the "lightning" to complement Tyler's "thunder."
There is no guarantee that Farmer is going to succeed as a tailback. His prior body of work is primarily as a wide receiver who has shown some obvious skills with the ball in his hands. But we just don't know how he is going to adjust to the physical nature of running the football. You also have to wonder how this impacts the other tailbacks who are still looking to establish their roles within the offense. For all of those uncertainties, however, it looks like Kiffin is focused right now on the potential gains of the position switch. If Farmer can come in and provide the difference between a 5-yard gain and a 30-yard gain or more, it could have a dramatic impact on the rest of the offense and the entire team.
If you think back to 2002, the entire USC team took off midway through the season, once Mike Williams became the big-play weapon for Carson Palmer. Whether Farmer can have a similar impact remains to be seen, but the coaches were clear to note multiple runs against ASU that had the potential for big gains but were held to lesser runs because Tyler didn't have the burst to get through the hole. If one or two of those stops could be turned into explosive runs it could have been the difference in that game and the rest of the schedule.