Schwarzer's deal expires in June.
Talks are currently in process and Jol said: "He (Schwarzer) can go on for the next one or two years but it's not like he is 22 and has another 10 years left in him.
"But how old are goalkeepers? If you look for evidence of them being 44-45, I can't see it. So 40 is quite remarkable.
"They (Australia) will go to the World Cup and he wants to be there. He will be 42 and then he will come back to us hopefully."