Having fallen out spectacularly during their time together in Ipswich, Ireland's latest captain has revised the opinion he voiced in 2010 when he suggested Keane ruled the East Anglian club by fear.
Certainly anxiety was uppermost in the Scouser's mind back then when he took the dramatic decision to take "a picture of me puke" as evidence that a stomach bug he had picked up was genuine. The photograph was forwarded to Ipswich's physio as way of explaining his absence from the following night's game in Exeter.
"It wouldn't surprise me if some players are terrified of him," Walters said a month after that incident, by which stage Ipswich had sold him to Stoke.
"In my case, his words went in one ear and out the other. You never know where you stand with him and that was the fear factor he brought in. I respected him as a player, but maybe he can't get his point across as a manager.
"There's a way of going about bollocking people. At Ipswich, it became personal a few times."
Time moves on, though, and so do managers. When Walters criticised Keane, he had yet to be capped by Ireland and Keane's relationship with the FAI then was as volatile as it was with his one-time captain. Now, they are back in the same camp and the tune Walters plays now sounds is dramatically different.
"We had a laugh together when we spoke last week," said Walters. "Everything was fine. I said a while back that if I was chairman, I'd give him a go as a manager because I was impressed with him at Ipswich.
"I really enjoyed how he was with people. I was captain there and enjoyed it but then I wanted to go to the Premier League and he wanted me to stay so it wasn't going to be all cuddles or anything. When we met up, we had a laugh about it."
Given the characters involved, it would be no surprise if they did, because prior to their blow-up, Walters was Keane's go-to-guy at Portman Road. Carved in the same image of his then manager, the 30-year-old has a streak of determination which has brought him all the way from League Two football to international captaincy.
"I haven't had the easiest route to get here," he said. "I was at Hull but my daughter was ill and that was a key reason behind how I ended up at Chester because, as a family, we wanted to be near home to avail of the support network there.
"I kept working hard and you get what you deserve. I will keep the armband. My very proud mum (who died when he was 12) was looking down from above. It is the proudest moment of my career."