I think he's been thrown to the wolves partly by the system, he isn't a lone forward currently.
We looked at our best going this season int he second half against Stoke with the following front 3:
Sandro----DCL----Rooney
DCL through the middle for his hold up, aerial ability and harassing defenders.
Sandro for his pace, looking to get in behind and to get shots off.
And finally Rooney dropping deeper to feed them or link up with others.
I'd like to see it more but suspect Koeman will seldom start both Sandro and DCL given that we have no other strikers.