The England U-19 international joined United on a season-long deal from Arsenal after spending two months of last season at Elland Road, where he helped them to promotion from League One.
Simon Grayson believes the winger's versatility - he can play on either flank or just behind the striker - could see him gain a regular first-team spot.
"He's exactly the type of player I want - hungry, with bags of enthusiasm, skill and pace. He's going to be a key player for as long as he's here," Grayson told the Yorkshire Post.
"He's coming from Arsenal so his ability can't be questioned. They bring kids through the proper way.
"He can play wide left, wide right and just off a striker so his versatility will be useful, but he's always been an option. Last season he really impressed us."
Source: PA
Source: PA