If he plays the rest of the year like he has been playing, then you have to. He's been off-the-charts good the past several games.
They still need more help in the front court. It's too bad they got nothing out of Vesely and very little out of Booker and Singleton. Those are three first round picks. They also got rid of Crawford for nothing. Those are all reasons I'd still fire Grunfeld. His weird fetish for Euros that can't play - Satoransky, Pecherov, and others I'm forgetting. If you let Grunfeld pick who to draft again, he'll blow it on another soft Euro with no skills.
At least Seraphin is coming around. He, Nene, and Okafor are a solid rotation but they need another good player there since Nene and Okafor are old and injury-prone.