The Reds signed the winger from Porto for a transfer fee of £42.30 million back in January.
Since then, Diaz has scored six goals and registered five assists in 27 appearances for Liverpool's first-team.
In other words, the Colombia international has proven to be a good signing.
However, Diaz was always going to be a success at Anfield going by Lijnders' scout report on the forward.
"Counter-press impulse will improve easily within our style and training. Will become more intense with this. More aggressive with this. By FAR the best player (at Porto). I HAVE NO DOUBT," he shared with Liverpoolfc.com, as quoted by Anfield Watch's Twitter account.
"Jurgen responded to this report with: “He is a game-changer.” I texted back: “Absolutely, literally for them and figuratively for us.” We hoped we could get the deal done."
Anfield Watch Verdict
Lijnders possesses a brilliant football brain. The aforementioned scout report backs up that particular argument.
There is not much that Diaz can't do. The winger can score, create, press and tackle. Diaz is perfectly suited to the intense nature of the Premier League.
The exciting thing about the Colombia international is that he is only 25 years of age. Diaz is far from the finished article, which is obviously exciting.
But, only time will tell if that is to be the case.