Keane has hammered the United defender at times during his career at Old Trafford.
Advertisement
Advertisement
But he said on the Overlap: "I was harsh on Harry Maguire for footballing reasons and obviously we do a lot of (Manchester) United matches – obviously he's struggled at United, had a tough time with England – but more so club level.
"We're on about the mental health of players, and I've crossed the line with Maguire – I mocked him a little bit and it's not nice.
"I've played the game, I know how hard it is, but I'm also big enough. I bumped into Harry a few months ago and I apologised to him. Sometimes as pundits we get it wrong as well, but there is a point where you go, if it's personal then you're crossing the line."