Kuszczak played against West Ham last week and then expressed the hope that he would not be waiting long for another opportunity.
For Foster, 25, the wait has been even more frustrating following two loan spells at Watford and cruciate knee ligament surgery that limited him to a single appearance at Derby last term.
But Ferguson is a big admirer.
"I can only go on what I see of that lad and in terms of first-team football, that means the Derby game last season," said the United manager. "But, considering it was his first game for a year, it was a magnificent performance.
"From that, what we see of him in training and what we saw of him at Watford, I would say he is England's No1.
"The problem for the lad is that he has just recovered from an injury and Edwin van der Sar is there.
"It doesn't make it easy for him. But he is young and his time will come."
