I think its worth a shot because Turbin will definitely be in line for major touches when Lynch is out. Also the Shanny backfield is always fluid so even if Morris gets carries this game he's never a lock for more down the road. If you want to still take a chance on Morris tho, I'd also consider dropping Celek as there are probably going to be plenty of Tight-Ends of his caliber on waivers this season and baring an injury you'll only be starting them once with Gronk locked in as your TE#1 (k. rudolph, z. miller, j. cook, g. olsen, m. bennett, s. chandler, m. lewis, h. miller....just to name a few).
EDIT: Also you can never have "too many runningbacks" as one person said above. They are harder and harder to come by as the season goes on and make EXCELLENT trade bait.