The People says Liverpool plan to sell Coates to fund a bid for Williams.
Gremio can sign Coates AFTER the European window shuts as their deadlines are different - and that is a problem for the Anfield club.
Rodgers would want to spend the money to find a replacement - with Swansea's Williams a big target - but his bosses are anxious.
If Liverpool sign Coates' replacement before selling him it puts them in a poor negotiating position.
So they will ask Gremio for a concrete bid in the next 72 hours.