Schrock and Younghusband disappointed with Philippines' inability to break down stubborn Singapore
The Azkals spurned a number of chances to win the game especiially after Singapore midfielder Hafiz Sujad was sent off in the 34th minute for a dangerous challenge on Phil Younghusband.
“It's not enough for us,” Schrock told FourFourTwo. “When you are 11 playing against 10 for 50 or 60 minutes, you have to do better.”
Schrock, 30, played in an advanced position, saw his 16th minute shot tipped over by in-form goalkeeper Hassan Sunny and then had a second half shot blocked.
“We had chances – I had chances too – but we could not take them and we had to settle for a draw but for us, it is not enough,” he lamented.
The former Eintracht Frankfurt star was impressed with Singapore's defending: “They did what they had to do and they did it well. Obviously, they parked the bus. We had the time and the opportunities but you have to take them.
"If you don't then you cannot win games.”
“Now we have to learn from this game and then look forward to the match with Indonesia.”
Philippines captain Younghusband was also downcast, stating: "It is two points lost, we know that.
"When the other team goes a man down, especially in the first half then you have to take advantage and we did not manage to do that.”
Younghusband, who played in midfield, paid tribute to Singapore's defensive abilities, especially after they were reduced to ten men.
“They made it hard for us and we had to work hard to make our chances. They did what they needed to do to get the point."
Now the Philippines must look forward to Tuesday's clash with Indonesia who lost 4-2 to Thailand in the opening game.
“We saw that they have some skill and pace in attack and we know that they are a good team,” said the former Chelsea trainee.