Peter Bosz's time as Borussia Dortmund manager lasted just half a season back in 2017, but that was long enough to leave the Dutch manager with a good impression of U.S. national team star and new Chelsea signing Christian Pulisic.
The 55-year-old's time at Westfalenstadion coincided with a difficult period of time for Pulisic, who endured the U.S. national team's failure to qualify for the World Cup in October of 2017.
Despite that, Pulisic was a regular starter for Dortmund under Bosz, though a disappointing Champions League group stage elimination and an eight-match winless run eventually led to Bosz's firing and the hiring of Peter Stoger.
Since then Pulisic has dropped down the pecking order at Dortmund, and has since been snapped up by Chelsea in a deal worth $73 million (£58m), though he will spend the remainder of the season back on loan with Lucien Favre's team.
And Bosz, who is preparing to make his return to Bundesliga as manager of Bayer Leverkusen sang the praises of the 20-year-old, believing he has all the attributes to be a success in the English game.
"I think I understand the move to Chelsea" Bosz told Goal in an exclusive interview. "[The] Premier League is different. You've got to be physically strong, and he is, so we'll see.
"Chelsea's not easy because a lot of good players are there, but I think [Pulisic] has the quality to be successful at Chelsea.
"He's a good kid. He still is really young. When I worked with him in Dortmund he was really young, but really talented also.
"He's fast. He's got a good shot. His mentality is outstanding. He's always fighting, he's always working and he's a good player."
Bosz is back in the Bundesliga after having been hired by Leverkusen in December to replace Heiko Herrlich, with his new side currently sitting ninth in the table as they prepare to face high-flying Borussia Monchengladbach on Saturday in their first match following the winter break.
He will come face to face with former side Dortmund on February 24, who in turn restart their campaign against RB Leipzig on Saturday as they aim to hold off the challenge of Gladbach and Bayern Munich in the title race.