Michael Turner took over as the primary kickoff returner last year after Sproles broke his leg in the preseason. Turner averaged 26.5 yards per return, more than 2 yards better than Sproles' average in 2005.
Also, Turner will earn nearly $2.4 million this season after signing the highest tender for a restricted free agent. The Chargers will give him every opportunity to earn that money, and taking touches away from him is not the way to do that.
If Turner needs someone to spell him, Antonio Cromartie seems more than capable. Cromartie averaged nearly 30 yards per return last season.
As for punt returns, Sproles was never all that comfortable in that role to begin with. In 2005, he struggled to field the ball cleanly. Although he was doing a better job of that in training camp of 2006, he has yet to prove he can handle that role consistently in a game environment.
To compound matters, both of the Chargers top two picks in this year's draft can return punts. Craig Davis, a quick and decisive runner, seems to be the early favorite in that competition. There's also Eric Parker, who is steady if not spectacular.
If Sproles cannot win back his kick returning jobs, his chances of making the roster are slim. With Turner and LaDainian Tomlinson holding down the running back position, Sproles only offensive contributions would come in specially designed packages.
However, those packages may now be designed for Legedu Naanee, who lacks Sproles suddenness but has better versatility and tackle-breaking ability.
Just two years ago, Sproles was creating a buzz with his incredible speed and ankle-breaking cuts. He was an X-factor and a fan favorite. Now, he may be a long-shot to make the roster.