Keane has become assistant manager with Ireland.
Carragher wrote in the Daily Mail: "When I worked at Euro 2012 as a TV pundit, I spent a lot of time with Roy. We enjoyed plenty of battles on the pitch during our respective playing careers, but last summer in Poland was the first time I got the chance to really talk to him.
"What was abundantly clear in our conversations was his burning desire to get back into the game, as well as the passion he had for Ireland, regardless of what had gone on in the past."
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