Keane said: “It’s fantastic. I have been in this job (Sunderland) for two months and I think I have aged 10 years, so for him to keep going.
“It is good to see United back on top. They have had one or two difficult years but he seems to be building another new team there and all credit to him.
“The pressures of management are there for everyone to see, but at Manchester United even more so, so it is absolutely all credit to him.”
He added: “He knows football, he knows his players, and he knows his own club inside-out.
“We all want success very quickly and we all want it yesterday.
“He is a great example to everybody. Alex Ferguson was at United maybe three, three-and-a-half years before he got a bit of silverware, and the pressures at Manchester United are more than at any other football club in the world, probably.
“It gives great hope to all the other managers, but it still does not stop chairmen sacking managers.
“Hopefully the managers nowadays will get a bit more time – especially the young, inexperienced managers – to get the results everyone is looking for.”