Fury claimed a controversial split decision victory over Ngannou, in his first official boxing match, in Riyadh on Saturday night.
But not before Ngannou sent him to the canvas in the third round and made him go the distance.
One judge scored the contest 95-94 in favour of Ngannou, while the other two handed it to Fury 96-93 and 95-94.
But double world champion Saunders was far from impressed by Fury’s performance just a couple of months out from his heavyweight showdown with Oleksandr Usyk.
Tyson Fury defeated Francis Ngannou by a narrow split decision on Saturday night
Francis Ngannou sent Tyson Fury to the canvas with a thunderous left hook in round three
Billy Joe Saunders wasn’t too impressed by Fury’s performance in Saturday night’s showdown
In an Instagram post, Saunders suggested Fury has ‘too many yes men’ in his entourage
Writing on Instagram, Saunders said: ‘Too many yes men in camp, not switched on from [the] word go.
‘But he [will] be switched on for the Ukrainian.’
Usyk was watching ringside and his post-fight comments suggested he wasn’t quite sure how to read Fury’s performance.
‘I had an impression that he was playing. I’m not thinking about [whether he was playing possum] but I will be training 100 percent,’ the Ukrainian told Fight Hub TV.
‘But listen, it’s boxing. Maybe it was the element of surprise. Maybe. I think it was [a] show.’
Asked whether it made him feel more confident ahead of the pre-Christmas bout, Usyk said: ‘I don’t know, I have no idea.
‘Listen, [Ngannou] is a world champion at MMA, that was a hard punch. Then there’s the element of surprise. Maybe Tyson Fury didn’t take it serious, ‘Oh it’s an MMA fighter blah blah blah’. I don’t know.
Of course I was surprised [by the knockdown]. I watched the knockdown and I said, “Oh, oh, oh Francis! Be careful please!” I was saying, “Tyson! Jab, jab jab, move, jab!” I was saying that.’
Fury’s next opponent Oleksandr Usyk wasn’t quite sure what to make of Fury’s performance