Patrick Willis, Vernon Davis questionable for Thursday night

AP

As the 49ers prepare to try to snap a two-game losing streak against a team they couldn’t beat in two tries last year, a couple of key players are questionable for the game.

Linebacker Patrick Willis officially is questionable with a groin injury.  Willis didn’t practice on Monday or Tuesday.  Wednesday’s practice wasn’t complete when the injury report was released.

Tight end Vernon Davis also is questionable with a hamstring injury.  Davis, who missed the Week Three loss to the Colts, practiced Monday and Tuesday on a limited basis.

Also questionable are cornerback Nnamdi Asomugha (knee), tackle Anthony Davis (shoulder), safety Raymond Ventrone (concussion), and receiver Kyle Williams (rib, knee).

The following 49ers are probable: linebacker Navorro Bowman (wrist), center Jonathan Goodwin (elbow), running back Frank Gore (knee), guard Mike Iupati (shoulder), defensive tackle Ray McDonald (ankle, ankle), cornerback Carlos Rogers (knee), and defensive tackle Justin Smith (shoulder).

For the Rams, defensive end William Hayes (knee) and tackle Rodger Saffold (knee) are out.  The probables include tackle Joe Barksdale (not injury related), receiver Chris Givens (knee), linebacker James Laurinaitis (foot), tackle Jake Long (foot), safety T.J. McDonald (knee), tight end Mike McNeill (chest), running back Daryl Richardson (foot), and guard Chris Williams (foot).

The Rams were undefeated against the 49ers in 2012, with one win and one tie.