Who is the starting RB this week?

I am in a college fantasy football league and I've been eyeing LJ Martin for some time. I finally pulled the trigger and grabbed him off waivers this week.

I just saw that Aidan Robbins is potentially the RB1 for the team, but has been injured the last few weeks. Looks like LJ has been workhorse since the Robbins' injury. Any idea who will be the RB1 for the team this week against TCU?

I need to make another move and have to drop someone, so I am unfortunately considering dropping LJ now if he is in fact going to be second fiddle to Robbins.

TIA