Mane, who has scored six league goals this season, signed a new contract with the Anfield club on Thursday, following in the footsteps of his fellow attackers Mo Salah and Roberto Firmino who agreed long term deals in the last year, Reuters reported.
“I’m pleased that he’s signed this contract. It’s a big sign,” Klopp said ahead of the Premier League fixture at Watford today.
“If a player is in a good moment and you can extend his contract it is more than a signing, it’s a statement.”
Klopp said the contract renewal was further evidence that his best players didn’t have to leave in order to chase success. Liverpool had previously been unable to prevent Luis Suarez and Philippe Coutinho leave for Barcelona.
“It shows the change the club has made. In the past players thought they had to leave the club to make the next step. Now our boys think they can make the next step here,” Klopp said.
Liverpool is second in the Premier League standings with 30 points from 12 games, two points behind Manchester City as it chases its first league title since 1990.
Egypt coach Javier Aguirre had speculated that Salah could leave the Reds if they did not win a title in the next two seasons, but Klopp dismissed the threat.
“I’ll try to be nice,” the German said. “If he (Aguirre) doesn’t win in the next two years he has to move to another club or country... I don’t agree with that but it’s a free world and he can say anything he wants.”
Shifting his focus to seventh-placed Watford, Klopp said he expected a tough test at Vicarage Road where title rival Tottenham Hotspur suffered a 2-1 defeat in September.
“They’ve been good. They play good football, are lively, and well organised... with a good game-plan,” the German added.
“It will be interesting, they have quick wingers and good central midfielders. I saw the game against Tottenham and they were good. It’s a proper package... the best Watford team since I’ve come to England.”
Skipper Jordan Henderson is fit for the clash after missing England’s Nations League win over Croatia with a hamstring issue while fellow midfielder Adam Lallana is out with a minor knock.