Havertz - winger not a 'midfielder'. By midfielder I mean defensive midfielder (center), box-to-box, or attacking midfield (centre). Positions: #6, #8, #10.
There's no legitimate transfer rumours or stories of Kai Havertz leaving Leverkusen this January. His club are in 6th position in German League with genuine chance of European football next season; why would they throw that away? Best
report I've seen is in Indy, and 1 month old. They say there's no reason for them to sell. They believe they will get at least as much money in the summer for Havertz. There's no indication that the player wants out now. His club are not in dire financial straights.
Houssem Aouar - more realistic prospect from a known selling club. But you cannot describe him as 'world class'. Potentially W/C; but potentially not too. Also: why would Lyon sell him now when they can earn the same or more next summer?
Tonali. Far less realistic than Aouar. Italian players rarely move outside Italy too. He's still young, 19, so not experienced enough to make a big difference for us. Nor is he W/C yet. Another potential. Why not play Garner or Levitt?