With the game goalless at half-time but the Reds in control after Andreas Christensen’s sending off, they were dealt a blow when Henderson felt tightness in his thigh.
Klopp was forced to look to the bench and had no qualms about introducing a player whose move to the club from Bayern Munich was confirmed just two days earlier.
Asked about that call and a convincing 2-0 win for his team, the German said: “It was a different game in the second half obviously but I liked the whole first half already.
“I liked the way we tried to find solutions, I liked the way we took a difficult game. It was already good and I was ready for a very positive half-time talk with a few pictures of where we could've done differently.
“We had to move quicker, pass quicker, pass easier and stuff like this. Then, the red card happened and that obviously changed the game.
“We came in and Hendo said that he probably got a knock but wants to carry on. I said, 'No, we don't take any risks.'
“Then we had to make the decision and decided for Thiago because, even without training against 10 men, he's then pretty much the perfect player on that position, I would say.
“Everything he did today was completely natural. It was not all perfect but it was natural, so the passes he tries to play are natural. That's good, really good, nice.
“Clean sheet, Ali saves a penalty, Thiago debut. If Hendo has absolutely nothing, it's the perfect day.”
Sadio Mane netted both goals for the champions, the second coming after he chased down an attempted clearance from goalkeeper Kepa Arrizabalaga.
On that goal and the performance of his No.10 Klopp added: “I love that because we have these situations quite a lot – that we chase the goalie.
“I think in the first half Sadio was really close to blocking it there already but you just have to do it. I love it when we get the rewards for these kind of situations.
“The first goal was a nice piece of football, everybody involved pretty much. Firmino cross and then Sadio comes in front of his man, so it’s really difficult to defend. Good goal and gave the game the right direction.
“That's exactly what we have to show all the time, that's what we wanted to show today. I saw us today, I saw us playing football today and I'm completely fine with that. I loved it.”