Tim Hightower was originally drafted out of the 5th round last year with the expectations that he could one day be the Arizona Cardinals starting running back. The rookie made a name for himself early and eventually took over for the now-departed Edgerrin James. He was undeniably the best and most significant draft choice of 2008 and was a large part of last year's post season run.
This year has been an entirely different story. At one end of the spectrum you might say he's improved because he's already rushed for 139 yards more then last year and has increased his average from 2.9 to 4.4 yards per carry. He's became a reliable back in the receiving game and has also had a knack for picking up blitzes. After all of his improvements however, Tim Hightower should not be the starting running back for the Arizona Cardinals and here's why.
1. Five fumbles on the year. That number may not alarm some but when you narrow it down, he's fumbled the ball 4% of the time this season. That roughly means for every 24.5 carries he gets, there's a chance we'll see Timmy put the ball on the ground. What's really made matters worse is that all  of the fumbles that were lost were in the 1st half of games. Anytime that happens it greatly diminishes the Cardinals offensive momentum. If you want to compare the two backs, Beanie Wells has 4 fumbles on the year but at a 2% fumble rate, and for every 34 carries there's a chance we'll see Beanie fumble the ball.
2. Hightower doesn't bring break away speed/explosiveness to the offense. As we all know, Tim Hightower tends to show hesitation in the back field before making a cut. We've seen it many times last year and flashes of the same tendency this year. He has greatly improved that problem but the Cardinals offensive line is not one that opens an ample amount of time for the backs. When Hightower broke a 50 yard run against the Rams, it was clear that he didn't have the top end speed to make it to the end zone. Unfortunately, Hightower may never have the ability to take it to the next level like Wells. In only 139 rushing attempts, Wells already has 3 touchdowns of 10+ yards - Hightower has zero.
3. Tim Hightower fits the offense better as a 3rd down back. Most 3rd down backs need to excel at blocking and pass-catching, for the obvious throwing situations that come on 3rd down. If we look at his strengths, we already know that Hightower has become a very capable blocker and his 53 receptions (he's 17 away from the single-season reception record for a Cardinals halfback) show that he can certainly catch the ball. Hightower would also fit the description as the closing back with the change of pace he brings to the offense. His relentless style is one that would fit better with tiring the opposing defense in the 4th quarter.
When I say Tim Hightower should not be the starting running back, it's because Beanie Wells brings more explosiveness at the start of the game. I love Hightower just as much as the next Cardinal fan but I do feel that he's not quite ready to be the full time back. He's proved that he can get better in just one season, and if he keeps his work ethic strong and makes a committment he will have a good career in the NFL. If anyone wants to make a case for Hightower I'd love to hear it, because right now I believe Beanie Wells brings something to the table that Hightower just does not.