There are rumblings around the league about a possible trade in which the San Francisco 49ers would send the top overall choice to the San Diego Chargers for quarterback Philip Rivers. The 49ers would get a QB prospect who perhaps is better than any in this draft, and the Chargers would end up with three first-round picks after going 12-4 and winning the AFC West title last season. The 49ers have denied that the trade is being discussed. But if it were to happen, it would further jumble the top of the draft, perhaps something like this . . .
1. Chargers (from 49ers via trade) -- Braylon Edwards, WR, Michigan (4*) . . . They can part with Rivers because Drew Brees blossomed into a Pro Bowl QB last season, and they get the player at the top of many teams' draft boards.
2. Dolphins -- Ronnie Brown, RB, Auburn (2) . . . Coach Nick Saban says he'd take back Ricky Williams. But could he ever depend on Williams?
3. Browns -- Aaron Rodgers, QB, Cal (1) . . . The draft's top-rated QB, just ahead of Alex Smith, falls to No. 3 with the 49ers-Chargers trade.
4. Bears -- Carnell (Cadillac) Williams, RB, Auburn (8) . . . With Edwards off the board and WR Mike Williams perhaps too similar to Muhsin Muhammad, the Bears opt for an upgrade at RB.
5. Buccaneers -- Cedric Benson, RB, Texas (5) . . . They need a centerpiece runner.
6. Titans -- Adam (Pac-Man) Jones, CB, West Virginia (6) . . . A perfect replacement for Samari Rolle.
7. Vikings -- Mike Williams, WR, USC (7) . . . The pressure would be on to replace Randy Moss, but he'd be a perfect WR complement to Nate Burleson.
8. Cardinals -- Alex Smith, QB, Utah (3) . . . They can't pass if one of the QBs falls to them.
9. Redskins -- Antrel Rolle, CB, Miami (9) . . . They need a No. 1 receiver, but they might need a CB even worse.
10. Lions -- Derrick Johnson, LB, Texas (12) . . . There are some questions about his ability and willingness to take on blockers head-on.
11. Cowboys -- Troy Williamson, WR, South Carolina (11) . . . Perhaps a bit of a stretch at No. 11, but he's a receiver with big-play capabilities.
12. Chargers -- Shawne Merriman, DE, Maryland (10) . . . Merriman is in demand as an off-the-edge pass rusher who could play DE or outside LB.
13. Texans -- Alex Barron, T, Florida State (14) . . . They need a tackle after failing in their pursuit of Orlando Pace.
14. Panthers -- Mark Clayton, WR, Oklahoma (19) . . . Carolina gets a receiver after releasing Muhammad in a salary-cap move.
15. Chiefs -- Erasmus James, DE, Washington (17) . . . The Chiefs get much-needed help on defense.
16. Saints -- Carlos Rogers, CB, Auburn (15) . . . This draft is full of intriguing prospects at CB.
17. Bengals -- Marcus Spears, DE, LSU (21) . . . Cincinnati is building a formidable young defense.
18. Vikings -- Travis Johnson, DT, Florida State (18) . . . Minnesota continues to bolster its defense after getting a receiver with the first of its two opening-round picks.
19. Rams -- Jammal Brown, T, Oklahoma (13) . . . Pace stayed, but Kyle Turley probably will have to be replaced.
20. Cowboys -- Demarcus Ware, LB, Troy State ( -- ) . . . He's moving up draft boards quickly as an outside pass rusher.
21. Jaguars -- Dan Cody, DE, Oklahoma (16) . . . Jacksonville needs to stabilize the DE position after being plagued by injuries and a lack of depth at the spot last season.
22. Ravens -- Channing Crowder, LB, Florida (20) . . . The club's once-imposing LB corps isn't quite as overwhelming any more.
23. Seahawks -- Shaun Cody, DT-DE, USC (23) . . . A solid, versatile player.
24. Packers -- David Pollack, DE, Georgia (22) . . . A defensive play-maker.
25. Broncos -- Brodney Pool, S, Oklahoma ( -- ) . . . It will be interesting to see if Pool or Georgia's Thomas Davis is the first safety taken.
26. Jets -- Khalif Barnes, T, Washington (24) . . . They lost a starting tackle, Kareem McKenzie, to the Giants in free agency.
27. Falcons -- Roddy White, WR, Alabama-Birmingham ( -- ) . . . Atlanta needs help at WR with Peerless Price's inconsistencies.
28. Chargers -- Darryl Blackstock, LB, Virginia (31) . . . Not a bad first-round haul for San Diego under this scenario.
29. Colts -- Fabian Washington, CB, Nebraska (32) . . . One of the fastest players in the draft.
30. Steelers -- Heath Miller, TE, Virginia (26) . . . Clearly the best tight end available.
31. Eagles -- Matt Roth, DE, Iowa ( -- ) . . . Philadelphia lost a DE that it wanted to keep, Derrick Burgess, in free agency.
32. Patriots -- Barrett Ruud, LB, Nebraska (29) . . . Champs need to do some patching up at LB, CB and along the offensive line.
*Draft slot in The Post's previous mock draft.
Dropped Out: Thomas Davis, S, Georgia (25); Reggie Brown, WR, Georgia (27); Vincent Jackson, WR, Northern Colorado (28); Anttaj Hawthorne, DT, Wisconsin (30).