Football's governing body FIFA was unable to immediately confirm on Tuesday whether Hassan had already earned a record 179th cap against Kenya on Monday because of uncertainty about the status of that match.
The Kenyans fielded an under-23 side in the friendly while their senior team remained in Nairobi for an African Nations Cup qualifier on Wednesday, prompting confusion over whether Egypt's 5-0 win would be recognised as a senior international victory.
Even Hassan was unsure about the number of caps he had collected.
"The Egyptian FA asked the Kenyan FA to hold an international friendly between the Egyptian and Kenyan first teams and they accepted that," the 36-year-old told Reuters in a telephone interview.
"Kenya didn't say they would play their Olympic team. Whatever the story is I will play against Niger to remove any doubts regarding who is the most capped player."
Zamalek midfielder Hassan, who made his international debut in 1995, drew level on 178 caps with Saudi Arabia goalkeeper Mohamed Al Deayea in November when he came on as a second-half substitute against Brazil in Doha.
The Egypt veteran has been given every opportunity to chase the record over the last 12 months.
Last year when the team decided to blood youngsters in two 'dead' Nations Cup qualifiers, Hassan was the only senior player kept in the side.
Egypt were scheduled to play a 2013 Nations Cup qualifier on Wednesday but were granted a postponement after 74 fans were killed in a riot following a league match in Port Said stadium on February 1.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.