PISCATAWAY -- Frustrated Rutgers University students who failed to get their tickets in the mail to see President Barack Obama's speech at Sunday's commencement ceremony will get another chance.

Students can go to the Rutgers Athletic Center in Piscataway between 9 a.m. and 1 p.m. Saturday to inquire about missing tickets, said Greg Trevor, a Rutgers spokesman.

Students can also email tickets@scarletknights.com if their commencement tickets did not arrive in the regular mail at their houses or dorm rooms by Friday afternoon.

"They can get the tickets emailed to them and print them out," Trevor said.

It is unclear how many Rutgers graduates and their families failed to get their commencement tickets and parking passes. University officials said the commencement envelopes containing the tickets were expected to arrive via regular mail by Friday.

Some frustrated students have taken to social media to complain about missing tickets and parking passes and long waits to speak to representatives at the university's commencement office.

"What happens if the parking pass doesn't arrive by Saturday? I spent 4 hours on the phone trying to reach the commencement ticket office," one student said on Rutgers' Facebook page.

Obama is scheduled to deliver the commencement address at High Point Solutions Stadium in Piscataway at 12:30 p.m. Sunday. He is the first sitting president to deliver a graduation speech at Rutgers, which is celebrating its 250th anniversary.

More than 52,000 people are expected to attend the ceremony, including 12,000 graduates from Rutgers' New Brunswick and Piscataway campuses.

The president's visit prompted unprecedented ticket and security restrictions for Rutgers' commencement ceremony. Graduates were limited to one ticket for themselves and three tickets for guests, whose names had to be given to Rutgers several weeks ago.

Graduates from Rutgers-Newark and Rutgers-Camden were allotted one ticket each to sit in the stands at the ceremony. Rutgers also held a lottery last week for students to get one extra ticket each.

Gates to the stadium open at 8 a.m. Sunday. Rutgers officials are recommending graduates and their guests allot at least two hours to park and get through security into the stadium before the ceremony.

Kelly Heyboer may be reached at kheyboer@njadvancemedia.com. Follow her on Twitter @KellyHeyboer. Find NJ.com on Facebook.