Posters here have an incredibly short memory.
A year ago, Gunnarsson was almost universally considered a bonafide Top 4 defenseman here, with some even claiming he was a Top 2. Now, he's "overrated," "terrible," "not an NHL defenseman." On the former, the ironic part is that many of the very same people now deriding him as "overrated" were the ones who were pumping his tires last season.
Gunnarsson's struggling this year, that much is evident. It shouldn't matter why (injuries, poor preparation due to the lockout, etc.), all that matters is that he is. The right course of action here, in my opinion, is to give him the opportunity to sort out his play. He's earned that. Play him on the third pairing, limited minutes, and resign him this summer to a cheap contract. The 27+ minutes he played last night was far in excess of what he should be playing at this point.