Thiago was a 73rd minute substitute at St James' Park.
Klopp enthused, "We could see a lot of moments how good a footballer he is. Now we have to see how he reacts and all that stuff. We have another game in four days. James Milner played a super game in midfield after an injury break. Nat Phillips did his job against, really strong against 100% strikers.
"A really good game but not the result we want."
Klopp also said, "I think we had four 100% chances. We have won against Newcastle before with fewer chances. Tonight we didn't but we accept that. I am happy with the things I saw tonight and I can really work with that.
"The boys are frustrated and rightly so but not about the performance. It is a basis to build on for the next few days, weeks, months.