3. James Robinson
James Robinson's career has been derailed by injuries and the concerns of him being a viable long-term option. Robinson appears to be healthy right now as he recently had a workout for the Indianapolis Colts but he would be on a team already if there were not long-term concerns.
In fact, Robinson signed a multi-year deal with the Patriots this past offseason that fell through because of injury concerns. Robinson was then picked up by the New York Giants only to be released in late August.
While the long-term concerns are valid with his past the Chargers do not have to worry about that. In theory, the Bolts would just be getting someone who could help bridge the gap now and make the running back room more well-rounded this season.
One huge aspect of the offense that is lost when Ekeler is not playing is the pass-catching ability at the running back position. Joshua Kelley and Elijah Dotson simply do not come close to being as reliable of targets in the passing game.
Robinson is not on Ekeler's level (as Ekeler is one of the best in the sport) but the thing that makes him a good option is his dual-threat ability. At the very least, Robinson could be a pass-catching target for Justin Herbert while Kelley handles the bulk of the running.