Roy Keane tends to make headlines whenever he speaks.The fiery Irishman, who is deservedly remembered as one of the best midfielders of the Premier League era thanks to his hugely successful 12-year spell with Manchester United, always speaks his mind and isn’t scared of upsetting people.Keane’s words often cut deep and a host of footballers - current and former - have found themselves on the receiving end of his forked tongue.On Monday night, Keane turned his attention to some of the players he fell out with while working as the Republic of Ireland’s assistant manager.A WhatsApp conversation by Stephen Ward with details of an explosive training ground bust-up involving Jonathan Walters and Harry Arter was leaked online and just how hostile Keane’s relationship was with several members of the Ireland squad.

Keane aimed fire at all three players while speaking at a Cadbury’s Off The Ball roadshow in Dublin on Wednesday - but it was his comments about Walters which came across as particularly brutal and unnecessary.

"Harry Arter went to Cardiff on loan, they got relegated," Keane said, per the Telegraph. "Wardy can't get in the Stoke team at the moment and they're down at the bottom of the league."

On Walters, he added: "He talks a good game.

Imagine if he'd won a trophy. He goes on the TV about how he was harshly treated by me. He's crying on the TV about his family situation

"Maybe he should lie low for a while. Have a look at his medals? That wouldn't take long. We got beaten by Wales. Jon played. Jon didn't have a good game. Wardy played, he didn't have a good game. They need to go back see how bad they were.

The comment about Walters ‘crying on the TV’ was a horrible low blow.

Walters revealed in May that he’d been through the hugely traumatic experience of losing his brother in the same week that his wife lost a baby, per the Irish Sun.

His daughter was also diagnosed with scoliosis to complete what Walters described earlier this year as a “triple whammy”.

Walters spoke emotionally on Irish TV and was praised for speaking so honestly about his grief - but Keane has used this, unfortunately, as an opportunity to have a dig at the former Premier League forward.

In what appears to be a response to Keane’s words, Walters tweeted a photo of himself wearing a boxing glove alongside the caption: “Insert face here”.

Unlike most, Walters clearly isn’t scared of Keane and it’s hard to blame him for feeling angry.

A lot of people believe Keane has crossed the line with his latest comments and it’s hard to disagree.