Keita produced a standout display on his competitive bow for the Reds, playing the full 90 minutes after his £52.75 million move from RB Leipzig in July.
He initially shone in his natural midfield role—composed and ever-willing in possession, robust and hardworking off the ball—before offering another outlet out wide late on.
Speaking after the game, Klopp praised his ability to slot in immediately, picking up from where he left off in Germany.
“[It was] nice. An absolutely good performance, of course,” he told reporters.
“After six weeks I don’t make the difference between a new players and another player, because it’s exactly the same importance that Milly and Gini are ready to make the next step in their development.
“Naby’s in because he’s a really good footballer, and he obviously settled really quickly.
“It’s a similar style of play and a similar position that he played at Leipzig—he can play different positions, but I think the No. 8 is his best in the moment.
“So that’s all cool, he had a lot of help from the players around him today: Sadio works really hard, and the same with Gini and Milly and Robbo.
“That’s really good. I’m pleased, absolutely, but that’s what we expected.”
Mane, who scored two of the Reds’ four goals on the opening day, was already familiar with Keita from their brief spell together at Red Bull Salzburg.
But reunited at Liverpool they are set to take a big step forward, and the No. 10 was impressed with his new team-mate’s first foray into life in the Premier League.
“I’m happy for him. He played very, very, very good and everybody was happy with the job he did for us,” he told LFCTV.
“At the beginning it isn’t easy, especially for the new players learning with the guys.
“And I think he’ll do better and better for us because he’s got great quality.”
The Reds now have a seven-day break until their next game, which comes away to Crystal Palace, and that could provide with an even tougher challenge.
But on the evidence of his first outing, Klopp and Mane are right to predict a bigger impact from the 23-year-old in the months to come.