With the Reds' injury problems mounting, Klopp included the 17-year-old in his 18-man selection for Saturday's Premier League meeting with Crystal Palace at Anfield.
Brewster failed to emerge from the bench as the hosts were beaten 2-1, but the manager insists he would not have hesistated to call on his talented teenage forward in the right circumstances.
And, though Klopp admits Brewster is unlikely to be involved when his team's fitness issues subside, he is delighted with the progress made by the England U17 international this term.
"Rhian made outstanding steps in the last few months," the German told reporters.
"The Talent Group are training one time a week here at Melwood with Pep Lijnders and I can see them then.
"I've known him for probably more than a year and how it is with boys at his age, they grow and that’s good.
"He is physically stronger, a wonderfully skilled boy, real striker, good finisher, fantastic work ethic and all that stuff.
"But, if all players are fit in the squad, then he will not be in the squad in the moment, of course not, why should he?
"He's 17 years old now and already plays U23, that's a wonderful step for him [and] the next step in his development.
"So all is good. If all the other players are fit then Rhian is not involved in the matchday squad but that's not a problem.
"He was on the bench last week because we thought he deserved it and we could use him in the right moment.
"The game was not for this but it doesn't mean that it will not happen in the future. He's on a very good way, honestly, a very, very good boy."
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Klopp also explained how Brewster, who was today called up by England U17s, has made waves among the senior squad with his approach to training at Melwood.
He added: "He was excited about it, he was happy about it. He told me after I said to him that he was in the squad, 'I have a washbag but I don’t have a suit'. No problem!
"He has a lot of respect in the squad, nobody thought, ‘Who is this?' They know him because he is an ugly opponent, a difficult-to-play opponent in training sessions.
"All good and I am sure it was nice for him."