Tyler Adams
Krystian Bielik
Possibly Emile Smith Rowe (I mention him a lot... I don't know if Arsenal would sell but he is one whom definitely interests me)
This one is probably unrealistic, but rumors are that Lampard could get sacked -- Mason Mount (or one of the many other "attacking mids" they have.
Left Back is a very tough position for us imo. We definitely need someone who can cover (maybe a full fledged backup). Someone mentioned it (i forget who) but we shouldn't be going out to sign backups, we should be signing players to first team roles that knock the current player to the bench. I just don't know who would buy for a 'reasonable' price that is an immediate upgrade. Rico Henry gets mentioned a lot but I don't know if 1. He's an immediate upgrade on Targett, and 2. would be worth the price that Brentford would want for him. (i also have mentioned a few times that he is a SHA fan as well)