BBC Sport chief football news reporter Simon Stone:

Watching Obi in the flesh, first against Preston last month and then against Chelsea last week, showed the striker has plenty of positive attributes. He is tall, strong athletic – and rapid.

It is easy to see how he was noticed by Arsenal – and many others – soon after arriving in London with his family from Denmark, and why the Gunners had high hopes for the youngster, who qualifies for Denmark, England and Nigeria.

When the deal went through in October, he proudly declared: “I am very happy to sign with this amazing club. Time to focus and achieve all my dreams.” He then signed his first professional contract when turning 17 late last year.

Obi was eased in at his new club as he needed to get over a niggling injury. But it has not taken him long to make a sustained impact.

Obi initially went largely unnoticed against Chelsea last Wednesday at Leigh Sports Village. Then he scored. And again. And again.

United were a goal behind and not playing particularly well when Jaydan Kamason chipped a pass into the right attacking channel. Obi arced his run across the Chelsea defence, then held off a defender before applying the finish.

He didn’t have to wait long for his hat-trick, turning home his second – and United’s fourth – from a low cross, before sweeping home a loose ball to complete his treble after a couple of wasted opportunities.

He even has a range of celebrations, using Rashford’s trademark finger to the temple when he scored his second.

Obi left the field to the loudest ovation of the night, getting a warm hug of congratulation from head coach Adam Lawrence on his way off.

“I’d like to see him in the first team,” said Steve Owens, a United fan from Bolton who was at the Chelsea game.

“He’s always in the right place, is good with his feet, is fast and can finish. He has definitely got it.”