The undrafted rookie with the best chance to stick is SMU's Shawnbrey McNeal. He will try to take advantage of the fact San Diego traded up three times during the draft, leaving the team short on selections and unable to acquire a third running back.
McNeal (5-foot-9, 194 pounds) transferred from Miami to SMU as a junior and posted 236 carries for 1,188 yards (5.0 ypc) and 12 touchdowns. He also caught 31 balls for 283 yards and two scores. He entered the draft as a junior due to his family's financial hardships; he was told by league officials he would likely be selected between rounds four and six.
McNeal's snub makes him one of San Diego's most motivated players. He will look to carve a niche on special teams and possibly contribute as a third-down back and change-of-pace runner.
WR Jeremy Williams
Another offensive playmaker in the mix is Tulane receiver Jeremy Williams (6-foot-1, 205 pounds). He somehow fell through the cracks despite finishing last season with 84 catches for 1,113 yards and seven scores.
Draft analyst Chris Steuber ranked Williams as a top-15 pickup in undrafted free agency. Here is what Steuber said about Williams in that article: "A smooth wide receiver that runs crisp routes and possesses strong hands, Williams disappointed scouts at the Scouting Combine when he ran a 4.59 in the 40. He improved his time to a 4.48 at his Pro Day, but teams wondered if his production at Tulane was inflated because of the competition he faced."
The third offensive player to watch is tight end Dajleon Farr. Like McNeal, Farr is a Miami transfer. Farr relocated to Memphis for his senior season, where he started five games and caught 14 passes for 76 yards and a touchdown.
Farr (6-foot-5, 252 pounds) is far from a finished project, but he has athleticism and experience on special teams. If tight ends coach Rob Chudzinski can help to polish Farr's skill-set, he has a chance to stick as the No. 3 tight end.
Will a rookie offensive tackle make the final roster? Discuss in the message boards.
Michael Lombardo is a member of the Pro Football Writers of America and a long-time contributor to the Scout.com network. His analysis has been published by the NFL Network, Fox Sports and MySpace Sports. He has followed the Chargers for more than 15 years and covered the team since 2003. You can see more of his updates by following him on twitter.