..............The 19-year old, who can play at centre-half, right-back or in central midfield, goes straight into the squad for the match with Rushden on Tuesday.
Seagulls boss Steve Coppell has snapped up Rehman after an injury to captain Danny Cullip.
"It's an opportunity to get some first team football," said Rehman.
"This season I've been in central midfield, but it doesn't matter what position I play, I just hope I can do a job for Brighton.