Atletico Madrid have spoken to Chelsea about a loan for Nicolas Jackson, with a potential obligation to buy.The London club would prefer an outright sale, as they attempt to offload a number of squad players ahead of transfer deadline day in eight days' time. With Aston Villa also considering Jackson, any move could have a knock-on effect on multiple other transfers.Chelsea themselves are understood to be open to a versatile attacker should they complete enough outgoings, with Marcus Rashford an option that has been broached.Atletico securing Jackson could meanwhile smooth Julian Alvarez's departure - potentially to Barcelona or even Arsenal - in what is already a protracted saga.If Jackson is to go, however, Villa is currently seen as more likely due to the expectation it would be a permanent move.Atletico are understood to have approached Chelsea about a number of differently structured loans for the 25-year-old Senegalese attacker.