The Brazilian has been heaping praise on the Liverpool boss.
The Brazilian has been in great form in front of goal in 2016, crediting Klopp for giving him the confidence to perform.
And the Liverpool playmaker told the Martch edition of the club's official magazine: "[He's] the best manager I've worked with. I don't say that because he picks me all of the time. It's because of his mentality and personality.
"He gives confidence to all of the players. He knows what your potential is, so he always says just one or two words to give you confidence and show trust.
"That's important for players. I think everybody likes working with him and we are all improving because of him."
Firmino is one man who has vastly improved under Klopp and the biggest question of all is who has improved the most?
Adam Lallana's form has shot up, Emre Can has got better, the defence is more solid and Daniel Sturridge is actually fit and playing...
Next up for Liverpool is the second leg of their Europa League last-16 tie against Manchester United in the Europa League. Going into that, Klopp was lucky enough to have a weekend off with his Reds side.
But that fortune is long overdue considering how busy Liverpool's schedule has already been this season...