Milan interested in Celtic's Ajer and Fiorentina's Vlahovic: the situation

Milan are preparing for the Rangnick era by identifying areas to improve the squad: a right winger, a central defender, a mezz'ala and at least 2 forwards. For the attacking options, other than Schick, there is an idea to make an effort for Vlahovic, who is condered among the best for his age and that he is compatible with Rebic. For the defence, other than Upamecano (a potential costly transfer), Celtic's Kristoffer Ajer is well-liked, but Milan is aware of the fact that they are in competition with multiple Premier League squad for the defender's signature.