Former Basel manager Thorsten Fink has told ESPN FC that Xherdan Shaqiri possesses world-class natural footballing ability like Lionel Messi does and believes he can go on to become the "best player for Liverpool."
Shaqiri has continued to impress in a Liverpool shirt after the Merseyside club triggered a £13.5 million release clause in his Stoke City contract in July.
The ex-Basel attacker scored his second goal for Liverpool against Fulham on Sunday and has been directly involved in five goals in his last six appearances.
"Cristiano Ronaldo, he worked for what he achieved," Fink, who managed the Swiss international between 2009-2011, said. "But Messi, he had it.
"He didn't have to work for this talent. Ronaldo must work for this -- work with this body, work with everything. For me, Messi has this talent. That's also for Shaqiri.
"He has this talent to play. If he works very professionally, he can be the best player for Liverpool -- not only a player. Every time the aim must to be better and make the next step. If you play for Liverpool not every week, it cannot be enough for him. His aim must be to play every week."
Fink, who is now manager of Swiss side Grasshoppers, managed Shaqiri when he was teenager, having broken through from the Basel academy. The German initially used him as a left-back before moving him further up the pitch, where he could have a greater impact.
"He's smart and it was pleasure to work with him," Fink said. "He played very well as a left-back. I thought he was the best left-back I saw after Roberto Carlos. But every time his aim was to play forward.
"He was very creative. He did things what you were not aware [he could do]. Sometimes he plays passes in deep, he shoots very well. He could cross very well, his ball control was very good. He had everything what you need for a perfect player. He was explosive.
"My aim was for him to be more professional. He was professional, but there were small things what I wanted to give the player on his way to be one of the best players, to play for Liverpool or Bayern Munich.
"With his possibilities, it's not enough to play for Stoke. He can play for the biggest club in the world because of the talent he has. That's what I wanted.
"In this time I had him, we were like twins because I know what he thinks, I know what he wanted to do. But he also gave me everything what I wanted. When I say: 'You play left-back', he played there fantastic. When he played in the offense on the right side, he played fantastic.
"Everything [is there] for the perfect footballer. The only thing is: 'Can you make the next step, Xherdan?' If you want to play for Liverpool or Real Madrid, Bayern Munich or Man United, and you want to play every time -- not just be the man who sits on the bench -- you need more professionalism.
"Now he had it, what I heard, and it's important that he had a good coach and looked to him."
In 2012, the sought-after Shaqiri left Basel at the age of 20 to join Bayern Munich, where he would face stiff competition in the form of Franck Ribery and Arjen Robben for regular game-time.
Liverpool made an approach to sign Shaqiri in 2014 but were blocked by the Bundesliga side. Shaqiri later joined Inter Milan in a six-month spell before ending up at Stoke in the summer of 2015.
"For me, I think it was a little bit too early to go to a big club," ex-Bayern defender Fink said. "It's normal, as a young player, that you need one step more. Bayern Munich had Ribery and Robben, and they couldn't let him out. Then Xherdan didn't have this patience that you need at this age.
"But I understand at this age of 19 or 20, you have to play because the best thing is to play, you need practice. At this time, he didn't have the right patience for this. Maybe another club was the right step for him, now like Stoke City and then he goes to Liverpool.
"Now he made the right step -- go to Stoke. He worked on his fitness I think and he plays with the same style as when he was 17. I like his style. He's a street footballer. Teams need more street footballers."