Last season fighting broke outside the stadium after Leeds' 1-0 victory.
Doug Smith, the Leeds ticket office manager, said: "We have done everything we can to stop tickets falling into the wrong hands.
"Any away supporters spotted in home areas will be escorted out of the ground by stewards."
The visit of Manchester United to Elland Road is usually the highlight of the season at Elland Road and normally tickets sell out weeks in advance.
But there have been extra tickets available this time leading to gate-crashing fears.