Keano explained in The Sun: "Brian Clough famously lasted just 44 days at Leeds but, as he went on to prove, that did not make him a bad manager.
"Who is to say that Andre Villas-Boas cannot do likewise and show his time at Chelsea was just a blip?
"I'm not saying he's going to turn Tottenham into European champions like Clough did with Nottingham Forest, just that his time in charge at Stamford Bridge need not define him as a manager.
"I do see similarities between Villas-Boas' time at Chelsea and Clough's Elland Road stint.
"Both had impressed in their previous jobs before moving on to a bigger challenge.
"The pair tried to stamp their authority on dressing rooms where there were some well-established players who had already achieved considerable success.
"It didn't work out for either of them but it doesn't mean that they should never get a chance in the dugout again."