Pat Nevin has told Celtic to "aim high" with their next manager - and put forward two suggestions.
The likes of Robbie Keane are being strongly linked with the post, while Martin O'Neill could yet stay on. Jens Berthel Askou is out of the running after leaving Motherwell for Toulouse.
Ipswich boss Kieran McKenna is another to have been linked and despite winning promotion to the Premier League, Nevin thinks Celtic should go for him.
He told Grosvenor Casinos: "Kieran McKenna has shown a fabulous commitment and a fabulous attitude to stick around when there was a chance to jump before.
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"Most Ipswich fans will accept that McKenna has done a great job for them and if he goes now then fine.
"McKenna works well for Celtic. He’s the right age, his profile's good. And the football's not bad either. Celtic aim high and McKenna is a high aim."
Another ambitious candidate could be Thomas Frank, out of work after being sacked by Tottenham.
Nevin added: "Robbie Keane has done a good job in several places, but has he done the sort of stuff that Thomas Frank's done?
"Thomas Frank's available and I have to say although it didn't go well for Spurs, I think that was a very Spurs problem!
"I actually don't think his credibility's suffered too much. There are certain people in the game who you like, and you’d love to see them doing well. He’s one of them. But there's a whole host of candidates."
