As for returning kickoffs, the team appears ready to hand that job over to Michael Turner. Although less evasive than Sproles, Turner is more decisive and powerful. He probably won't break as many long runs as Sproles, but he will break more tackles.
The team has other options here, too. Drayton Florence returned kicks as a rookie and could be given the opportunity to do so again. There is also Cletis Gordon, a rookie who returned two kickoffs for touchdowns while at Jackson State.
"I think about cathing the ball first, making the first guy miss, and getting up the field as fast as possible," Gordon explained of his punt return skills. "I was blessed with good instincts and just try and go out there and go full speed. One of my strengths is my vision."
Can he make an immediate impact?
"I am confident in my ability to punt return or kick return," Gordon added.
There are plenty of candidates for the punt return job as well. Keenan McCardell and Eric Parker both returned punts last season, but the team would prefer not to subject its starting receivers to any further risk of injury.
The other choice here would be Antonio Cromartie.
Marty Schottenheimer has said that Cromartie will not be used in that capacity, but Cromartie himself tells a different story. "I have game-changing ability," said Cromartie. "I'm going to come up with big plays on defense and on returns, too."
All that leaves is replacing Sproles on offense. That is a little easier, as Ray Perkins appears to be the man for that job. In fact, Sproles and Perkins have very similar playing styles.
Perkins is a second-year player from South Eastern Louisiana, where he played for coach Hal Mumme. After Perkins signed with the Chargers prior to last season, Mumme had the following to say about him: "His versatility is what sets him apart. I always saw him as being a really great third-down back in the NFL."
While Perkins will in all likelihood assume Sproles' roster spot, fullback Andrew Pinnock may become the team's third runner. Now is a time when having a fullback with Pinnock's running ability becomes an invaluable asset.
If the Chargers don't find any of these options appealing, they could always look for outside help. That doesn't seem necessary at this point, as they are a deep and talented team and there are no free agents still available who deserve a roster spot more than current bubble players like Gordon and Perkins.
But if the team insists on bringing in a free agent to return kicks for the season, Tamarick Vanover is still available.