The BBC pundit was asked his opinion on the Norwegian.
Deila has been heavily criticised during spells at Celtic - despite this only being his second season with the Bhoys.
But Sinclair wants to give the Norwegian his support if he is able to deliver all three domestic trophies this campaign.
So far in 2016, Deila's results have been very positive indeed.
Celtic are on form, having won their last four on the bounce, and are six points clear of Aberdeen at the top of the Scottish Premiership table.
Plenty are backing Deila, especially considering recent results.
But critics will point to performance levels dipping this season and many, it seems, would agree with Sinclair.
Deila needs to deliver the treble, even if Celtic were very hard done by in the Scottish Cup semi-finals last season. Is it harsh to say 'Deila out' if he doesn't win it or is Sinclair spot on?