His four-game NFL suspension over linebacker Jo-Lonn Dunbar has agreed to terms with the Rams and will re-sign with the team today pending a physical.

Dunbar’s return comes at a time when the Rams’ defense is struggling both to stop the run and the pass.

In addition the status of his September replacement Will Witherspoon is uncertain for Sunday’s game with Jacksonville because of a hamstring injury.

Dunbar finished second on the team with 157 tackles a year ago was fourth on the team with 4½ sacks and added two interceptions and two forced fumbles. He brings a much-needed physical presence to a defense that has been a big disappointment four games into 2013.

Dunbar’s suspension was for violating the NFL’s substance abuse policy. The Rams don’t have to clear a roster spot for him until the end of this week.