He has been included in their 18-man squad for the trip to Denmark and will at least be on the bench for the Europa League last-32 tie.
Poole left Newport County for Old Trafford in August but only recently received international clearance to feature in English football.
The 17-year-old played 15 games for the Exiles before his transfer.
Poole has been given squad number 41 by United manager Louis van Gaal, who signed the player for an undisclosed fee on the same day he paid an initial £36m for striker Anthony Martial.

Historic Scotland has pledged £500,000 towards the scheme which also has council and private sector support.
The project is due to get under way in April and finish in 2021.
It will include the refurbishment, improvement and reuse of historic buildings in the town centre.
They include Stranraer Museum, the former Harbourmaster's Office and Gillespie's Bakery.
Grants will also be available to property owners to allow them to undertake essential external repairs to their premises and contribute to the wider improvement of property condition across the town.
Dumfries and Galloway Council said the cash injection would ensure major improvements and restoration of some of the most historic parts of the town.

Of the 4,150 full-time firefighters across Wales' three fire brigades, only 40 are black and minority ethnic (BME).
Five of north Wales' 880 firefighters are BME, in mid and west Wales it is 15 of 1,390 and in south Wales it is 20 of 1,880. BME people make up 4% of Wales' population, according to the latest census.
Fire minister Mike Penning said diversity was "not an optional extra".
"Firefighters, like police officers and other local emergency services personnel, should reflect the communities they serve and we expect fire and rescue authorities to do much more to improve BME... representation," he added.
The Fire Brigades Union (FBU) said the fact just 4.4% of firefighters in England and Wales were BME was "totally unacceptable".
The figures, released by the Department for Communities and Local Government, show 10 firefighters, all in south Wales said "don't know" when asked about their ethnicity.
Although there are no statistics for a breakdown of Welsh cities, in places like Greater Manchester, just 2.8% of firefighters are from an ethnic minority compared to 16.2% of the population as a whole.
Mick Nicholas, the most senior black member of the FBU, told BBC Radio 5 live the fire service had been "inconsistent" at recruiting from non-white communities.

World number four Massaro, 33, won 11-8 12-10 11-5 in 35 minutes to become the second woman to win the title twice, after Malaysia's Nicol David.
"I'm one of the oldest on Tour and as long as I feel I'm still in contention to win titles, I'm happy," she said.
Compatriot James Willstrop was beaten 12-10 11-9 11-8 by Egypt's Mohamed Elshorbagy in the men's final.
Former world number one Willstrop, who is now ranked sixth, said: "To make the final was a great pleasure. I was loving every minute, apart from losing.
"Full credit to him, he stopped me playing so there are no complaints."
Wales Under-19 defender Regan Poole could make his Manchester United debut against FC Midtjylland on Thursday.
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The final element of a £1.7m investment package has been secured to finance a regeneration programme for conservation areas within Stranraer.
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Just 0.9% of Wales' firefighters are non-white, official figures have shown.
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England's Laura Massaro defeated world champion Nour El Sherbini to defend her Dubai World Series Finals title.