A January arrival from Salzburg, Minamino started for a youthful Liverpool in the victory at Anfield.
Klopp liked what he saw from the 24 year-old Japan international as Curtis Jones' 71st-minute stunner put the European champion into the fourth round.
"Super. Outstanding. Exactly the player we wanted, exactly the player we wished for," Klopp said. "In your first game in a team that you don't know, if it's a settled team it's already difficult, this team we threw on the pitch with more or less two sessions together and then showing this kind of game understanding, [his] football skills are exceptional, attitude is outstanding, leading the chasing pack so often in different situations.
"It was a nice add on to have Alex Oxlade-Chamberlain back because he looked pretty lively when he came on, trains only two days now and that's why he didn't start.
"But yeah it was super."
Liverpool, 13 points clear at the top of the Premier League, is next in action with a trip to Tottenham on the weekend.