The Seahawks — largely healthy for the first month — suddenly are suffering through an avalanche of injuries.

When they play in St. Louis on Sunday, they will be without four starters and two reserve defensive linemen and might be down to one tight end as well.

Already out were tight end Zach Miller (ankle), center Max Unger (foot) and linebacker Bobby Wagner (turf toe). Joining them is cornerback Byron Maxwell (calf) and D-linemen Jordan Hill (ankle) and Cassius Marsh (broken foot).

On top of that, wide receiver Percy Harvin (thigh) and tight end Luke Willson (groin) are questionable.

Marsh is out 6-8 weeks and, considering he has played in just 20.8 percent of the snaps this season and has not contributed much anyway, he could be placed on injured reserve. That would enable the Hawks to add a tight end — with practice squad player RaShaun Allen the likely addition. Cooper Helfet is the only other tight end; he would start if Willson cannot.

With Marsh and Hill out, Greg Scruggs figures to get his first playing time of the season. He had been inactive for every game until last week, when he was released to enable the Hawks to call up defensive back Steve Terrell.

The Hawks cut Terrell and re-signed Scruggs this week because Tharold Simon is back. The 2013 fifth-round pick will make his NFL debut Sunday, likely starting ahead of Marcus Burley. Simon missed last season with foot problems and sat out the first five games of this season after having knee surgery.

Wagner is out for an extended period of time — no surgery, but his foot is in a cast — and K.J. Wright will start in the middle, as he did last season when Wagner missed two games with a high ankle sprain.

Steve Schilling will again start for Unger, with Patrick Lewis the backup.

The many injuries mean young skill players Christine Michael, Paul Richardson and Kevin Norwood could all be active — especially if Harvin or Willson is out.