The German also had a dig at the Premier League for bringing the deadline forward to August 8.
Speaking after a 6-0 win over Tranmere Rovers, Klopp said the return of several injured and young players will act as new signings, while also not ruling out the arrival of players this summer.
He said: "We brought them in already, only you don't realise it. Rhian Brewster; Oxlade-Chamberlain didn't play last year; all the young boys today. They are all new players for us, that's all good.
"The transfer market is open until August 8. The whole of Europe had the idea to close the transfer window early and the only country that did it was then England, so we close it now three weeks before all the others.
"We will see what we do but I don't think it will be the biggest transfer window of all time."