Pogba put in a man-of-the-match performance as world champions France defeated Germany 1-0 in their opening game of EURO 2020 on Tuesday.
The 28-year-old has often divided opinion with his performances for Manchester United, with many of the opinion that his output at Old Trafford have not been of the required standard.
"Listen we keep talking about Paul Pogba," Keane said on ITV. "There's no doubt he's a talented boy. I still want more from him, particularly when he's playing for Manchester United.
"No doubt he's surrounded by probably better players and he's more comfortable in that environment with the French team. He plays on the left side and slots in.
"I think when he's with United, he maybe doesn't take responsibility, maybe there's too much responsibility or maybe there's not enough players around him who can take responsibility," added the Irishman.
"I know with France he is sharing this kind of responsibility with other players around. Maybe in Manchester (he is) isolated too much and maybe this is why he is feeling more pressure.
"Obviously there is a difference between the Pogba we know with France and the one we know at United."
