The Republic of Ireland's assistant manager was not particularly happy about Rooney's off-field activities.
That is because WWE star Wade Barrett didn't take too kindly to Keane's assessment of Wayne Rooney's recent appearance at a wrestling event in Manchester - where the England captain slapped the wrestler - and has thus, offered to "batter" the former Manchester United skipper.
Keane's comments came in the wake of Rooney's disappointing display during the Red Devils' goalless draw with PSV Eindhoven, which has left the club's progression to the next stage of the Champions League in doubt.
The former midfielder criticised Rooney's performance against the Eredivisie champions, before suggesting that he should have been concentrating on his own form - the 30-year-old has one goal in his last seven games in all competitions for Louis van Gaal's men - rather than appearing at the WWE event (via The Sun).
"Wayne was on about lack of composure and quality, but I think he was as guilty as anybody. He needs to step up to the plate," Keane said.
"You look at Wayne's legacy at Old Trafford, it's absolutely fantastic, his goals record is brilliant.
"But now he's the captain there’s more responsibility and I think he's got to do a lot more.
"I always question certain players what are they doing off the field.
"Last week I saw him slapping a wrestler and I'm thinking 'Why is he getting involved in all that nonsense?' There's no benefit to him. I'd have a look at that side of it," he added.
Barrett was informed of Keane's criticism of the United forward, and decided to thrown down the challenge to the pundit.