Pioli left Milan at the end of last season before making the move to the Saudi Pro League.
On the progress of Tijjani Reijnders, Pioli said: "During last season I always told him that he never put it in. I already knew him, I had seen a West Ham-AZ Alkmaar with my son and my other analyst and I said 'let's look at this player because I liked him'. For me he is a player of incredible intelligence, quality, class, but last year he had so many opportunities to score, even in training, because he has a great precise shot and he couldn't score, but it is part of years like that.
"The first year in Italy is always very difficult for the players because we are complicated, we are different. More strategic, more tactical, football is more difficult to develop, but I have never had a doubt about Tiji's qualities."
On Christian Pulisic, he continued: "He's another one of those players with an incredible mentality and quality. One of those with whom I had my first interview on video call, I was already convinced before because I knew him as a player, I had studied him for the characteristics we needed. I had seen him so focused, humble, so eager to face the new experience.
"Christian is also a top guy, as a player, he can play in many positions. He has the mentality of always giving his best, always positive, he was a pleasant player to coach."
And asked about new Milan coach Sergio Conceicao, Pioli also stated: "I speak from my experience, I believe that you have to go there and you must not know anything about what happened before, you must not ask 'what you did, how you defended, how you attacked, etc'. You have to bring your way of being, you have to be yourself, you have to believe in what you do and then slowly understand where you can get to and how you can achieve certain results.
"But I believe that Conceicao has clarity within himself of what he wants to be, of what he is and therefore he will try to bring his way of playing, his way of training, his way of approaching the team and then after that everything is unpredictable, in my opinion he is an excellent coach, so I wish him the best, but whether certain things will happen or not is difficult to predict."