It's very, very, very rare that I'd suggest giving a goalie back to back starts...this would be one of those times I'd suggest it.
meh, I wouldn't mind him playing in the second of the B2B. If Niemi performs against Tampa and Columbus like he has these last few games, might as well put Grosenick in to start the second of the B2B. There are certainly more difficult teams to have your first start against than Carolina, a taste of the NHL will be good for his development.
On the other hand, the Sharks floating around the .500 mark makes me nervous about playoff chances. I don't want to see them lose points on games they SHOULD win on account of a rookie goalie who shouldn't be playing...
I don't know, not feeling too hot about the Sharks right now.