Rangers have parted company with manager Graeme Murty.
Celtic suffered a 3-0 defeat to Zenit on Thursday night.
Debate has been aplenty on Twitter over Celtic's best starting line-up.
Celtic and Newcastle are reportedly interested in Dundee defender Jack Hendry.
The Celtic legend has been discussing his former team on Thursday.
The former Old Firm rival was discussing Mark Warbuton's Rangers side's draw at Ibrox last weekend.