via Dana Wakiji tweets,

Zetterberg not skating today in practice at the BELFOR Training Center, most likely maintenance day.

practice:
Mantha-Booth (taking Zetterberg spot)-Nyquist
Tatar-Larkin-Athanasiou
Helm-Nielsen-Abdelkader
Bertuzzi-Glendening-Frk

Ericsson-Daley
Kronwall-Green
DeKeyser-Jensen
Ouellet-Witkowski

added 111:28am, Wakiji...

PP units:
Frk-Booth (in Zetterberg's spot)-Nyquist-Mantha (net front)-Kronwall;
Tatar-Larkin-Athanasiou-Abdelkader (net front)-Green