The former Reds winger has warned against the counter-attacking capabilities of a Real side that comes into the second leg at Old Trafford in bullish mood after back-to-back wins against arch-rivals Barcelona.
Jose Mourinho's men carry an obvious threat, particularly with Cristiano Ronaldo in their ranks, and a tactical battle could unfold between the former Chelsea manager and Sir Alex Ferguson.
"The thing is both Real and United are counter-attacking teams," Sharpe told MUTV. "If we can let them have the ball a little bit, and they play in our half, then we can hit them on the break. They will try to do the same to us and, with us being at home, we may have to come out a little bit. It’s going to be an interesting game and there will definitely be goals.
"It couldn’t have gone much better for us in the first leg – to get the away goal and come away with a draw. We rode our luck defensively at times but that’s always going to be the case playing against one of the top teams in Europe.
"It leaves it wide open for Tuesday but Real Madrid are really impressive going forward. Our defenders and defensive midfielders, whoever plays on the night, have to be on top form to keep them out. I think both teams will score as we’re going to have to do well to keep them out."