#3 Price of Transfer
The Brazilian could cost Manchester United around £100m and as of now, it does not look like a wise investment. Coutinho is already 26 years old now and will be 27 by the time the transfer window opens. As such, there is very little return on investment opportunities for such an astronomical amount of money.
The Brazilian is a very good player, but he is not the superstar that the United marketing would be able to bank on. The Red Devils are already paying the price for a poorly planned transfer of another South American - Alexis Sanchez. Coutinho could demand similar wages and there is another risk of a transfer strategy going wrong.
But perhaps the biggest problem with the transfer is the quality that Manchester United would be getting for such a huge amount of money. The Brazilian will not score bucket loads of goals and as such, United could have a hard time justifying the transfer.