Liverpool fans blame the Liverpool Board of directors for going for Author Melo, they said Melo is a kind of player that do back pass, not the kind of the player that is needed in Liverpool squad. Maybe they are right but if he is not useful, Jorggen klopp won't say he want him, and it's not a long term contract, it's a loan due that would last for just a year. But even if Author Melo is a footballer that does back pass, Jorggen klopp would work on that, he would learn new style of playing under Jorggen klopp, he would know what Liverpool want and learn their play way, that should not be hard for him as a professional footballer that has been playing for long time, he has played under coaches, not only one coach.
When Thiago Alcantara first reached Liverpool, his playing style didn't match with Jorggen klopp style but he later adapt and things go well for him, sometime without Thiago Alcantara, the midfield collapse and that is what is happening presently, that is the reason why they go for Author Melo. Maybe the reason why Thiago Alcantara adapt with Liverpool's style is because he is fast, part of what Liverpool need but Author Melo is kinda slow of which didn't suit with Liverpool style, Liverpool's style of play is direct football, ball may be touched by more than two players and you'll see them inside the box 18 but Author Melo waste time by turning before he release ball.
I don't think Liverpool go for Author Melo because they really need him but because there is no other option, but even upon that, he was still choosen by Liverpool, it means Liverpool still need him in that squad, Jorggen klopp know what to do in order to train make him adapt with his style. Even when Fabio was signed from Monaco, Liverpool fans hate him before he adapt with the style Liverpool plays, it's at training that Fabio, Thiago Alcantara etc get adapt with the style Liverpool plays, so Author Melo can adapt as well. Adaptation of player still depend on the kind of player that he is. Mikel Obi also throws back pass at Chelsea, but before José Morinho go for him, he is an attacking minded player, so he adapt fast with different styles.
What is good for a coach is to find best out the players that are under him. People may think they swapped Author Melo for Mirale Pjanic at Barcelona, of which Pjanic is older than Melo even at Juventus, he didn't have playing time, but it still depend on the style that coaches plays, Klopp that choose him would find the best in him for Liverpool because I'm sure he is aware of the loan deal so as he support the deal, he definitely need him. Thiago Alcantara, Naby Keita are injured and Hedersson has joined them recently and his injury is not the injury that he can return back easily, hamstring injury is not an injury that is easy to come back and he's aged already, even Chamberlain is injured.
Recently, Jorggen Klopp said that he didn't have Champions league player in his team right now, they are all injured, maybe that is why he go for Author Melo that can play Premier league until the injured players come. As injury set in, Liverpool go for Author Melo, as Liverpool is in condition that they need player to be there until the injured ones return, just like when Barcelona need striker, they go for Pierre Emerick Aubameyang and he spent just six months in that club before Chelsea go for him now and reason they Chelsea go for him is still because they need a striker, if they later have better striker just like Barcelona have Roberto Lewandowski, they can still sell him.