PFA chief executive Gordon Taylor has expressed his concern at the coin-throwing incident during last week's Manchester derby that left Rio Ferdinand nursing a cut close to his eye.
Taylor believes the introduction of nets, which are used in other parts of the world, are the only solution.
However, Ferguson does not believe such a move would be the right answer.
And, aware his own club were in the spotlight three years ago when Craig Bellamy was struck during a derby encounter at Old Trafford, Ferguson wonders whether more vigilant stewarding within grounds would be a better way forward.
"We've seen netting behind goals in some grounds but I'm not so sure," said Ferguson.
"There have been a couple of occasions (in addition to last Sunday).
"It happened in our game at Chelsea and it happened in the derby.
"But it's not a consistent thing and I think stewarding is a better policy."