MANCHESTER, England -- Manchester United supporters are leading an initiative to improve the atmosphere at Old Trafford for Brighton's visit in the FA Cup next month.

Manager Jose Mourinho has been critical of United's home fans since arriving at the club and branded Old Trafford a "quiet stadium" following the 2-0 win over Huddersfield Town in the Premier League.

The Manchester United Supporters Trust (MUST) have been pushing the club to make changes to the seating at Old Trafford in a bid to improve the atmosphere.

And ahead of the FA Cup sixth-round tie with Brighton, they have agreed to let fans request to sit in L Stand, the section of the stadium usually reserved for away supporters.

"It is an experiment to show the club that if we can get groups of mates who want to be vocal sat together we can create the atmosphere we say we can," said Ian Stirling, vice chair of MUST and fans forum representative.

Old Trafford has included a permanent "singing section" in J Stand since the start of the 2014-15 season.

If the Brighton trial goes well, MUST are hopeful the club will allow more groups to be accommodated throughout the stadium.

"There are other things that need to happen, like moving the executive seats from the centre of the Stretford End, but we think that if we can get groups of like-minded fans sat together we can improve the atmosphere," Stirling said. "It's about showing the club we can deliver the atmosphere we say we can if they help us."