After the first drive, he didn't get a run again until the 2nd quarter, and only had 2 more runs for the entire half. That's only a portion of the equation though, as scheme differences come into play, as TB may have made adjustments.

Now I do think multiple backs is important in the NFL. Keeps the players fresh while the D-line gets exhausted, but if you think that a back can just walk onto the field after a long wait and roll off a 10 yard run, just as easily if he's in the game rhythm.... I just can't see it. A big part of being a running back is getting a feel for how the defense moves and what will be available to you.