Houllier is delighted knowing they're set to be confirmed Premier League champions.
He told the Mirror of Klopp: “He bought two players who made a huge difference – Van Dijk and Alisson.
“He spotted the weak points of the team and if you look at the results since Van Dijk and Alisson have been there it is phenomenal.
“Even last year I would say they nearly deserved to win the title as well. They had one defeat in 38 games and had 97 points.
“It was just because Manchester City were outstanding as well and had one more point.
“You have to give credit, which Jurgen did, to Manchester City who were phenomenal. City also won the title the year before with 100 points.
“Then the following season to have 98, that is tremendous and you have to acknowledge that."