Isaiah Pead says he hasn't been able to show it yet the electricity and explosion the speed and vision that made him a Cincinnati star.

"I don't think my best abilities have came out by any means" he said Friday.

But the question about the running back St. Louis used its fourth draft pick on in 2012 is starting to change. It used to be "When will Pead peak?" It's shifting to "Will he?"

With a less-than-stellar rookie season in the books and a rough start to his second year Pead has work to do. Saturday's preseason game against Green Bay offers his next opportunity to prove he should replace departed starter Steven Jackson instead of Daryl Richardson who seems to be settling into the role.

"I think Daryl played really really well last week" Rams offensive coordinator Brian Schottenheimer said Thursday. "I think Isaiah's definitely got to play some catch-up. But again we're not just looking at one game. He's got a whole preseason to look at. We were very pleased with the way Daryl played last week. They've both done really well in practice. Would I say Daryl has the lead? Sure but there's a ways to go and we expect good things from Isaiah this weekend."

Richardson having a leg up on Pead has been a consistent theme since both running backs became Rams in 2012. St. Louis snagged Richardson from Abilene Christian with its last pick the second-to-last in the entire draft. Richardson carried the ball 98 times for 475 yards in 2012. Pead totaled 10 touches for 54 yards.