The Villa midfielder has turned his back on Ireland after representing the country at youth level.
The 20-year old has represented Ireland at the under 17, 18 and 21 levels and while Keane was hopeful the talented youngster would stick with the country of his grandparents, he is now glad the saga is over.
“I’m not surprised by the decision,” said the Manchester United legend, in quotes published by the Telegraph.
“We were always hopeful. I’ve been asked this question a number of times, we’ve been patient.
“Jack had already played for Ireland and we were hoping he’d continue, but he’s made his decision and we move on. I didn’t cry myself to sleep when he made the decision. The player had a massive decision to make, he’s made it and we move on.
“I’m glad the saga is over. I’m relieved I won’t be asked any more questions about it. It wasn’t frustrating at the time. I’m glad the player has made a decision, he thinks he’s made the right one, but it’s not keeping me awake at night.”
Despite Keane’s brave face, Grealish’s decision will come as a hammer blow given he was one the most promising young player to emerge for Ireland in recent years.
The Aston Villa man now turns his attention to the England set-up and will be desperate to make an impact in time for next summer’s European Championship.
Whether or not he will be able to force his way into Roy Hodgson’s plans in time is another matter, but the England manager’s inclusion of Dele Alli in his latest squad is evidence young players will get their shot.
Grealish has shown flashes of his quality this season but now needs to put his niggling fitness issues behind him and piece together a run of productive performances over the next few months if he is to truly make his mark on the international stage.