Boss Chris Powell is waiting for the results of an X-ray on regular number one Ben Hamer, who injured his leg while warming up against Doncaster on Tuesday night forcing Ben Alnwick to make his debut and leaving no goalkeeping cover on the bench.
Pope, 21, only joined the Minstermen last week and kept a clean sheet against Morecambe on Tuesday night, but he may now be needed among the subs for Charlton's clash with Ipswich on Saturday.
"After we know more about Ben Hamer we'll speak to the Football League," said Powell.
"It's a shame because we wanted Nick to go out and get some games. Normally you can't call players back in the first 28 days but if you only have one fit goalkeeper you do get special dispensation."