Liverpool could be set for a busy final few days in the summer transfer window. With just four days left to do business in, the Reds are still yet to make a single new signing since the end of last season. While supporters will be hoping that will change between now and Friday, Sunday’s 2-0 win over Brentford showed that the Liverpool squad is still as strong as ever. Nevertheless, there is always room for improvement. And one area of the pitch Arne Slot had been to upgrade in earlier this summer was in defensive midfield. Having watched Wataru Endo in the early part of pre-season, there were …