All five of the midfielder's appearances for the Reds have come away from home and he missed much of the first half of the season with a serious knee injury.
Klopp compared Thiago to a "new signing" as he previewed the derby clash, saying: "To put the pressure a little bit off the situation I said we should sign Thiago in the window.
"Now he is here, let's hope he stays like this for a long, long, long, long time.
"The most important thing is he is fit and he trained. He had 90 and 45 minutes in the last two games.
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"We will see if he can play and which position he can play because there are different options.
"But it is really good to have him around now. He is a really good guy and an exceptional football player. It is like a new signing."
Thiago is likely to feature in a central midfield trio alongside captain Jordan Henderson and stalwart Gini Wijnaldum.
The establish forward trident of Mohamed Salah, Roberto Firmino and Sadio Mane are expected to feature, while things are less clear-cut in defence.
In the midst of Liverpool's centre-back injury crisis, Klopp has turned to teenager Rhys Williams and even plugged the hole with Henderson during the defeat at Southampton.
The Reds boss hoped Joel Matip would be fit to face United after the Cameroonian returned to training on Friday.
But if Matip is not available, Nat Phillips could get the nod alongside Fabinho, Trent Alexander-Arnold and Andy Robertson in the back four.
Goalkeeper Alisson is one of the first names on the team sheet and was hailed as Liverpool's "most important player" ahead of the match.
Liverpool predicted starting XI (4-3-3): Alisson; Alexander-Arnold, Phillips, Fabinho, Robertson; Henderson, Thiago, Wijnaldum; Salah, Firmino, Mane.