Liverpool manager Jurgen Klopp appeared to question Chelsea's decision to let go of Mohamed Salah as the Egyptian winger prepares for his debut season with the Anfield club.
Salah, 25, became Liverpool's record transfer this summer when the Premier League club paid Roma £39 million (Dh187.7m) for his services.
Salah moved to Serie A side Roma in August 2016 for a reported €15m (Dh63.5m) having spent the previous season on loan in the Italian capital, and the season prior to that on loan at fellow Serie A club Fiorentina.
During all three seasons in Italian football, Salah impressed. For Roma he was directly involved in 58 goals in 83 matches and was named the club's player of the season in 2016.
Salah caught the eye early in his career with a series of impressive displays for FC Basel in European competition, while helping the club win successive Swiss league titles. It was those performances in Europe that helped persuade Chelsea to part with £11m to sign him in 2014.
However, Salah was given few opportunities to shine in London, which led to the loan moves to Italy. Now he is back in the Premier League, and Klopp is convinced that, due to Salah's otherwise stellar career, his spell at Chelsea can be completely "ignored".
"A lot of players have shown it is quite easy to struggle at Chelsea. (Kevin) De Bruyne is one," Klopp said.
"The only thing that we really ignored was what he did at Chelsea. When he was at Basel, we (Dortmund) played them and we didn't know him. It was unbelievable. The moment I said 'let's go for him' he was already at Chelsea.
"Then he struggled at Chelsea because it was too early ... The question is 'what did you not see in him?' because he played all inclusive football. He was quick, he played a lot of games, he created goals and chances and he scored by himself.
"He is a left-footed and we don't have too many of them in the team. It all makes him really valuable for us.
"I'm happy for the moment but he needs to learn a lot. We have to start working on the physical part and the technical part."
Liverpool are in Hong Kong to participate in the four-team Premier League Asia Trophy and will face Crystal Palace on Wednesday.
