Fletcher does not believe the result would have been different had they started the game with other players.
Rangers managed to get a 0-0 draw from their meetings with United at Old Trafford.
“We were up against a resilient Rangers side and it didn’t matter who would have played,” Fletcher told Sky Sports News.
“They would have found it equally as difficult because they doubled up in the wide areas, they didn’t let us cross the ball and, even when we did cross the ball, they had three centre-halves in there to clear it.
“So, no matter who played against that, it was going to prove very difficult.”