While the former Southampton star missed the majority of last season with a badly broken leg, teenage full-back Riley admits he has cast an eye over the game style of the England international in a bid to further his own development.
"If you look at someone like Luke, he bombs forward all the time and is obviously a great left-back," Riley said in an exclusive interview with manutd.com.
"It's good watching him get forward but also defending as well. I'd like to take that into my game.
"I've not really played as a wing-back before but I definitely think that role could be calling my name, to be honest."
19-year-old Riley made his senior debut for United as a half-time substitute in the FA Cup against Shrewsbury Town on February 22 before making his first start at senior level in the Europa League against FC Midtjylland three days later.