During the winter transfer window of 2018, a South American star made it clear that he wanted to swap Premier League life for that in La Liga.
At the end of a protracted saga, those at Anfield eventually sanctioned a big-money sale and used the funds generated to invest in other areas of Jurgen Klopp’s squad.
They have thrived, becoming Premier League title challengers and Champions League finalists, while Coutinho is considered by many to have flopped in Catalunya.
Werner believes the 26-year-old will now be questioning his decision to walk away from Merseyside, with Liverpool having shown that they can attract and retain some of the best players in the world.
“As far as I'm concerned, there's no reason why any elite player wouldn't want to be playing for Liverpool,” he told the Echo.
“We have such a strong squad with a strong back office and a manager who I think is one of the greatest managers in world football.
“So I don't think there is going to be any players who if they were invited to play for Liverpool, wouldn't jump at the opportunity.”
Werner added on a player who has been linked with a return to England: “I would just point to the story of Philippe Coutinho.
“I have only good things to say about Philippe. But I think he left Liverpool because he wanted to play for one of the two big Spanish clubs.
“We tried to convince him that we had the club moving in the right direction and that he could experience big Champions League occasions by staying at Liverpool. I think he probably regrets his decision.”
Liverpool have spent heavily since agreeing to part with Coutinho, bringing in the likes of Alisson, Virgil van Dijk and Naby Keita.
Klopp has stated that there will be no repeat of that elaborate outlay this summer, but Werner says funds will be made available if the German identifies the right targets.
He added: “John [W Henry], Mike [Gordon] and I will leave the transfer business to those who know it so well – Jurgen and [sporting director] Michael Edwards.
“If they recommend someone then we will support that recommendation. Our role at FSG is to support the manager and the people around him in the best way that we possibly can.”
For now, Liverpool’s focus is locked on the present and a Champions League final clash with Tottenham at Wanda Metropolitano in Madrid on Saturday.