"Christian scored the decisive goal and that's the best thing you can do as a striker but he can play even better," Klopp told reporters on Thursday ahead on Saturday's league clash with West Ham United.
"You can make your life easier in games like yesterday when you take your first opportunity (to score).
"If you don't (take your first chance) you have to work to defend, to switch, to speed up and slow down. That's what we did."
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West Ham co-chairman David Sullivan had earlier revealed the Hammers made an approach for Klopp during the close season.
However, Klopp said it was not the right time.
"In the summer, I was not available. I'm sure I should say not too much about this," Klopp said.
"I'm lucky I had a lot of interest, West Ham is a good club but it was the wrong time, like all the clubs who approached me."
Captain Jordan Henderson was forced off 61 minutes into Wednesday's victory over the Black Cats as a result of discomfort in his foot.
But the manager insisted it was too soon to make a decision on the severity of his problem.
"(On Henderson) I have no update now. We have to wait a little bit because it was something with the heel but it could good for him we all hope. We have to see," Klopp said.
"Everybody knows Hendo is a real tough guy and yesterday he tried and then we saw it's not perfect... Now we have to wait a few hours more or a day or two and then we know more."
(Reporting by Shravanth Vijayakumar in Bengaluru, editing by Pritha Sarkar)
