Tottenham and Manchester United have asked the Premier League to allow teams to have more substitutes on the bench.
The managers of both clubs believe that there should be seven substitutes to choose from instead of five.
"Every club has players of squads of more than 16 players," said Ferguson.
"I didn't choose Darren Fletcher for the Arsenal game and that was a kick in a teeth for him and it didn't sit easy with me," added Ferguson.
The Premier League says it may look at the issue.
"If member clubs want to raise it then we'll look and discuss it as a league," a Premier League spokesman told BBC Sport.
"We've resisted the idea before because we feel it favours the bigger clubs who have bigger squads.
"If it was raised it would go to (our) summer conference, and if the clubs agreed it could be in place for the start of the 2008/2009 season."