It's official. The San Francisco 49ers have just clinched the 2006 Super Bowl.

After all, in '06, their star running back Frank Gore rushed for 1,695 yards, caught 485 yards' worth of passes, and scored nine total touchdowns. And Monday's free-agent signee, Brian Westbrook, rushed for 1,217 yards and amassed 699 yards via the air for the Philadelphia Eagles, accounting for 11 touchdowns. Too bad that was four years ago.

Brian Westbrook has averaged a catch for every three rushing attempts in his career. Cliff Welch/Icon SMI

Now Westbrook is 30 (he'll be 31 before the '10 regular season starts) and coming off a year that saw him limited to eight games and just 61 carries because of a knee injury and a concussion. And like Thomas Jones in Kansas City, Westbrook is forced to take a job on a team with an established back. Such is life when you're a running back on the wrong side of 30.

Though I do have him rated as my No. 6 running back, Gore provokes angst in me this year. He hasn't made it through a full season since those halcyon days of '06. He wasn't consistently effective last year, with 10 straight starts in the middle of the season where he exceeded 20 carries just once, plus with a sub-4.0 yards per carry average if you remove three exceedingly long runs (two of which came in the same game). I have him at No. 6 because everyone after the first four running backs has warts, and Gore figured to be in a relatively unthreatened starting position in the 49ers' backfield, something not many rushers can say these days.

Gore can still say it. Westbrook can still be explosive in bursts (he averaged a respectable 4.5 yards per carry in his limited action last year), but there are real questions about his knee holding up for a full season. The Westbrook signing seems a direct response to Glen Coffee's abrupt retirement, which to me means that this is San Francisco trying to find another body who can contribute if and when Gore gets hurt. Westy is that, but I'm afraid he's not much more. I'm not changing my rank of Gore one bit on this news. He's still scary to me, but he's also still pretty clearly a No. 1 fantasy back.

This is worse news for rookie rusher Anthony Dixon, who racked up 103 yards rushing and a touchdown on 21 carries Sunday against the Colts' reserves, but who doesn't offer much in the way of quickness or elusiveness. Whereas it seemed possible that Dixon would be an unquestioned second-stringer behind Gore once Coffee retired (I think we've all seen enough of Michael Robinson to know he wasn't going to be in the mix), now Dixon looks like a third-stringer, and perhaps a short-yardage option. His future is still intriguing, because he's a load. But this year, he's not draftable.