Keane enjoyed an impressive start to his coaching career at Sunderland, securing promotion from the EFL Championship, and securing survival in the Premier League inside his first two seasons in charge.
The Irishman then had a mixed spell in charge at Ipswich Town, before spells as assistant manager with the Republic of Ireland, Aston Villa and Nottingham Forest, with the latter role ending in 2019.
Since then, Keane has flirted with the idea of a comeback, but no project has persuaded him to accept despite his confidence over still having lots to offer.
"There was definitely part of me over the last year that feels, and I don't know if it's an ego thing, that I should have been a manager somewhere. I think I would have been a really good manager.
"I wasn't showing it. I wasn't going around saying 'I should be a manager'.
"I'm also doing TV stuff and I appreciate that work, I embrace it. But there was definitely something with me going 'I should be a manager somewhere'.
"You have extreme highs, I had it at Sunderland, you think things are great and then I went to Ipswich and you're battling just to get results.
"I don't miss being on the rollercoaster. But, I have the feeling I could have been a really good manager."