It probably won’t be known until very late in the week before the Packers’ next game against the Lions if the left hamstring injury that ROLB Clay Matthews suffered while attempting to sack QB John Skelton in the third quarter of the Week Nine win over the Cardinals will be sufficiently healed.

But with head coach Mike McCarthy saying only that Matthews was expected to be out “a couple of weeks,” the possibility that the Packers’ undisputed best defender could be sidelined for at least the Detroit game appears strong.

The way our sources on the Green Bay scene see it, while the Packers probably could get by for one game without Matthews — with the quartet of Erik Walden, Dezman Moses, Jamari Lattimore (eight snaps on the outside in the Week Nine win over Arizona) and newly activated Frank Zombo collectively picking up the slack — any more time off for Matthews could spell real trouble for a team that has been bombarded by injuries for the second time in three seasons.

Should Matthews sit out the Lions game, we hear the best bet to replace him in the starting lineup would be Moses, who is coming off a solid performance in the Packers’ last game, with Zombo, fresh off the physically-unable-to-perform list, backing him up. Whether Moses starts on the right side or the left side — with Walden moving to the right side that Matthews primarily occupies — remains to be seen.