The goalkeeper was speaking to the media ahead of the game on Wednesday evening, which the Gers take a slender advantage into – they turned around the first leg from 2-0 down to win 3-2 at Ibrox.
McGregor, who made a game defining save at 2-0 down, believes success will all come down to the Light Blues implementing the perfect game plan, which he thinks Steven Gerrard has excelled in producing during European competition.
The 38-year-old said: “It will be a difficult challenge; we saw what they were capable of last week and what they did in the first-half, and some of the second-half. I imagine it won’t be any different.
“From when the gaffer has come in our organisation has been spot on for the most in Europe but I don’t think it was last week.
“But in the periods of the game where it was it was very important to us and I think that is what helped us get the victory last week. Our organisation tomorrow has to be spot on.
“Because of the way the first leg went and what the result was my save probably was a big moment in the game.
“I think first-half we had a lot of chances too and we knew what we had to do, it was just a case of going and doing it.
“Compared to the first-half I thought we were a lot better in the second-half and we took our chances.”
Rangers come into the Europa League clash off the back of a disappointing draw with St Johnstone in the league but McGregor believes confidence should be high due to recent European displays – including wins over Braga’s rivals Porto and Feyenoord.
He continued:
“It has to be more on a consistent basis because that is what wins you things. I think as a squad we need to be more consistent.”