Wagner is a close friend of Klopp's and he has also worked alongside him at Borussia Dortmund.
He admires Klopp's dedication to the job and the way he gets the most out of his players.
Wagner told FIFA's official website: "Sometimes you need a little bit of luck to win a title, but he [Klopp] absolutely deserved this.
"He lives and breathes this job 100 per cent, he thinks about football or his team every minute of every day.
"That's the way good coaches are, you can't simply switch off from what might happen to the team tomorrow, next week or in an hour's time.
"What he's already achieved in the time he's had with Liverpool is incredible."