A young Scotland side were handed a hefty 4-1 defeat by the World Cup co-hosts, who will now step up their preparations against England next Tuesday.
Their Dutch manager Guus Hiddink was still not happy and feels his side should have piled on more goals.
"We got a bit showy," said Hiddink. "When your opponents are on the ropes, you must finish them off."
Scotland boss Berti Vogts said: "I saw a lot of bad things and I saw some small good things. The players were looking a bit tired but I don't know why. It was not good enough for international level.
"It was not what I wanted. I was very disappointed."
Meanwhile Kasey limped off the pitch along with team-mates Clint Mathis and Greg Vanney during the USA's 5-0 victory over Jamaica in their World Cup warm-up match.
Kasey bruised his left knee in a 51st-minute collision with Jamaica's Deon Burton.
Our keepers did not have a great time of it in friendies for their respective nations. Neil Sullivan conceded four in Scotland's thumping by South Korea and Kasey Keller hobbled off in the USA's trouncing of Jamaica.