This is very worrying. If Huff is out for long then the WR corp would be:
Maclin
Cooper
Smith
Matthews
Benn or Momah
That is a terrible group, not even considering that both Maclin and Cooper have been hurt in camp.
I really don't think that's as terrible a group as you think dude. It's not going to be a record beating group or anything, but it doesn't have to be. Maclin has a carrer average of like 800 yards per season on a team with DeSean Jackson. He's got a career average of like 13 yards per catch too. He has scored 10 TDs in a single season which is more than Jackson ever has. Maclin could be really good if he can stay healthy.
It's hard to say with Riley Cooper. I don't think he was even given a legit shake until last year because he had to contend with Jackson and Maclin for his entire career. But his yards per reception have been good his entire career. He could be a legit good receiver who never had time to shine and got it last year.
Jordan Matthews is a rookie, but pretty much everything we've seen from him has been solid except his first preseason NFL game. I think tomorrow he will be awesome.
Combine that with the run game and I think the offense is fine. The big problem is the defense and there's no sense in worrying about the offense when you've got way bigger problems.
EDIT: BTW, his AC sprain could be nothing. He'll miss tomorrow probably but if he's out of a sling already he will probably be in game 4, definitely available week 1. The hit he took was vicious and he came out pretty well considering.