49ers vs. Rams: What mix of players will be on game-day roster?

Update: News was just released that Demarcus Dobbs was arrested early this morning on suspected DUI and possession of marijuana. This would seem to point to Wilhoite being activated to replace Dobbs, who plays on every special teams unit. Dobbs is also a backup defensive linemen and the 49ers do not have many alternates at this spot. It seems likely that Will Tukuafu will be active, probably at the cost of one of the rookies. Of course this news came out JUST after I initially posted this article.

With Sunday's game against the Rams fast-approaching, the 49ers will have to decide how their game-day roster changes without the services of recently injured players Kyle Williams and Kendall Hunter. They've made a few roster moves this week, including promoting LB Michael Wilhoite to the active roster from the practice squad. Wilhoite tweeted today that he would be playing in his first game Sunday, so it would seem he's going to be active.

What does that do to guys like LaMichael James and A.J. Jenkins, rookies who were hoping that they would get a chance to dress this week with absences at each of their positions? Why do I ask how a LB being activated could affect a RB and a WR's chance of suiting-up Sunday? Well, it's complicated...

My first thought was that Brandon Jacobs simply steps-in for Hunter as the second running back and Randy Moss plays more snaps with Williams out. That would open up two spots over the roster that was used last week, though. If Wilhoite dresses, that leaves just one.

I started thinking throughout the week that maybe we WOULD see LaMichael James (LMJ) active this week as the third RB, since Anthony Dixon is primarily a special teams player and the loss of Hunter's dynamic, shifty runs outside could be significant. That would leave the slot WR spot somewhat open, or at least thin, as Mario Manningham is really the best fit there with Crabtree and Moss on the outside.

So I took another guess and said, "What if Delanie Walker plays more 'Y-flex' (TE flexed out away from the formation into the slot) and simply runs some of the same routes the slot WR normally would?"

That would mean you might want him playing less on special teams, so perhaps Wilhoite would fill Walker's role there and AJ Jenkins (AJ) would not dress on Sunday.

But what if the 49ers want to dress just three RBs, as they did for much of the 2012 season thus-far, and decide that they need at least one of them to be a shifty threat and the other must be capable of carrying the load between the tackles? I'd tend to think that means Frank Gore, LMJ, and Jacobs are those three guys, rendering Anthony Dixon useless.

In this case Delanie Walker could play his normal role and Wilhoite would take over for Dixon on STs. Now if you're not using Walker as a quasi-slot WR, you can activate AJ to fill that role, at least as a backup/extra player if someone get's tired or knicked.

With Wilhoite being active, special teams really are the key here, and guys like Walker and Dixon are of similar size to the LB. I could see him replacing either of them on STs so they could have a role on offense, or not dress at all (only in Dixon's case), opening a slot for one or both of the rookies to don the 49ers red and gold on Sunday.

Just something a "Ninerd" (thanks James Brady) like me thinks about two days before a game.