Louis Murphy has been used as a big play guy this season, with occasional flashes. He's also dropped a few passes that would have been sure touchdowns.
If Lafell doesn't go, I think Murphy has an outside shot at putting up solid numbers, but you also have Armanti Edwards (who has been earning more playing time) and Joe Adams (who seems to finaly be out of the dog house) to compete for touches. The biggest threat to Murphy however is David Gettis.
He was activated off of the PUP list about 4-5 weeks ago and has been inactive most weeks, but in my opinion he's the best receiver of the group. I think he'll definitely be active if Lafell doesn't play, and I could see him filling that third receiving option role (behind Smith and Olsen). Call it a gut feeling, but Gettis is a talented guy and I think he makes his presence known.
I was at the game in Charlotte for the one time he was active (against Denver) and he was getting great separation from his defenders. Unfortunately, this was the game where Cam was getting sacked on every play, so he never had the time to get the ball to Gettis. He looked good though.
Gettis isn't the best special teams option, so he's been inactive for that reason...but this injury should help him get on the field. I think Murphy will need a touchdown to be a big fantasy contributor, but he'll probably get a few catches, with a deep shot or two down the field.