Mignolet is one of four summer deals completed by the Reds in this window.
Liverpool have also added Kolo Toure, Luis Alberto and Iago Aspas. The big question now is will they manage to bring in any others before the window closes on deadline? That, and whether they'll manage to hold on to Luis Suarez, of course.
There's talk a highly rated Brazilian midfielder might be a target. The player in question made a big move in January, but financial problems at his current club could leave the door open to a move. He'd be a great capture if they got him.
Another name to consider is among the best prospects in Europe. Another midfielder, and another man who has proved himself in the Champions League, this player would be met with great excitement should he sign for Liverpool.
Here's B/R's Will Tidey calling fact or fiction.