The AC Milan midfielder, who is on loan from Los Angeles Galaxy, is set to play on his former club's home patch for the first time since his departure from United in 2003.
Milan trail the English champions 3-2 after their UEFA Champions League last-16 first leg in the San Siro, and face an uphill task if they are going to overcome the deficit at the Theatre of Dreams.
Much has been made of Beckham's return to his old stomping ground, and the England stalwart insists he is excited, not scared.
He told Milan's TV channel: "If I play on Wednesday I won't be frightened but I will be excited because I played in that stadium for many years and I know what it means to be a Manchester United player.
"I know what it means for opponents to play there."
Beckham is fully expecting Wayne Rooney to play in the match, despite the Red Devils frontman being a doubt with a knee problem.
"I'm sure Rooney will play," he added. "I think he's had some problems in the last few days but he had the whole weekend to recover.
"He's a fine player and he'll want to participate in the match. Alex Ferguson will certainly use the best possible formation."
In the build-up to the initial tie between the two clubs, much was said about Beckham's relationship with former manager Sir Alex Ferguson.
However, the 34-year-old has once again moved to quash rumours of any bad feeling.
He remarked: "Alex Ferguson gives a lot of advice to players and he's one of the best football coaches.
"He protected his players but he made me understand when I was making a mistake."
BECKHAM Excited by MAN UTD Retrun
