Keita is set to officially become a Liverpool FC player this summer after having completed a deal to move to Anfield last summer.
The Guinea international will link up with his new team-mates in the coming weeks as he looks to force his way into the starting line-up at Anfield next season.
Keita is set to officially become a Liverpool FC player on 1 July and he will be hoping to prove himself as worthy of a regular spot in the first team in the coming months.
And his RB Leipzig team-mate Wenger is backing Keita to be a big success and fulfil his potential at Anfield.
Speaking to German outfit Die Welt, Werner said: “To become world-class you have to play in the big teams and then play big games like the final or semi-final of the Champions League.
“World class… I’m not yet a world class striker. For me (Robert) Lewandowski, Luis Suarez and Antoine Griezmann are.”
“To become a world class player, I probably have to play on a club level in an even better team.
“Naby Keita has not become world class with us either, maybe now he’ll be at Liverpool.
“I have four or five years left to learn, and then become world class.”
Liverpool FC have already begun their summer recruitment drive by signing Brazilian midfielder Fabinho from Monaco last month.
The Reds are likely to be on the lookout for a number of new signings this summer as they bid to build a team capable of challenging for the Premier League title next season.
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