Maybe they are thinking of having a good defensive back. He is adaptable to lot of defensive positions so I think its a good choice given how United are performing defensively. They need a strong presence in defence and right now there is none. They could work out without Martial as he already is not finding much playing minutes after arrival of Ronaldo and to be honest it would be hard to compete with him for the position. Better offload from one department and add strength to other.
Arsenal 'ahead' for Insigne
Arsenal are reportedly the front-runners for Napoli forward Lorenzo Insigne.
The Italian winger is available on a free transfer as early as January and Corriere dello Sport have claimed that the Gunners are 'ahead' of the opposition should he elect to leave his current employers.
https://www.football.london/arsenal-fc/transfer-news/arsenal-transfer-news-live-lacazette-21735787