Per Christopher Michel, United are struggling to finalise a deal for Obi Martin because of "very complicated" legal issues. The Athletic have previously reported that the two clubs have been in talks over an acceptable compensatory fee, as United cannot simply sign him on a free transfer.

Obi Martin's contract with Arsenal expired at the end of last season but because of his age, the Gunners are due a fee because of the role they played in his development. They had attempted to convince the 16-year-old to stay, but United beat off serious competition to bring him in.

Obi Martin was prolific for the Gunners' Under-18s, scoring 32 goals in 21 games for the club. He is also a Denmark Under-18 international.

United plan to finalise Obi-Martin's signing swiftly but it remains to be seen if they will be able to do so without going before a tribunal.