You improve the club in other areas.
You get another striker to replace llorente, you get yourself a much needed playmaker if the 4-3-1-2- is the formation of choice, and you get a top class LB.
You are never going to replace Pogba with another Pogba. That doesn't happen.
You shore up other areas to improve the starting XI, keeping in mind that a midfield that consists of Marchisio, Vidal, Asamoah, Pirlo, Pereyra, and Sturaro is still pretty damn good.