The on-loan full-back, 22, has enjoyed his most productive season to date, playing 18 consecutive games since joining Pompey in January having also had spells with Sheffield United and Preston.
He told the Portsmouth News: "This must be my best-ever season because I am playing that many games. I've been playing here for 18 games in a row now and I'm enjoying it.
"I need the experience to get into that first-team squad of Manchester United, that is my plan. Portsmouth is giving that to me. I have a lot of big players around me that help me day in, day out in training sessions and in games and that has really benefited me.
"Being in the Championship, it's fast and it's hard for 90 minutes so it's about trying to keep calm on the ball and when the pressure is on you.
"I feel I am more comfortable now. The confidence is there so that's good for me as well. I just try to do my best every game. I am improving all the time and this season has been the best season for me."