Manchester United striker Wayne Rooney could also be involved as Pearce does not have to submit his final Olympic squad until midnight on July 9, a week after the Euro 2012 final, paving the way for players to compete in both tournaments.
Pearce said: "I think the players will dictate their availability, I really do. I think the players will be very excited by being part of the squad - if they're good enough to get in it - and I think they will dictate to the clubs in some ways.
"I wouldn't close the door on anyone, certainly an individual of Ryan Giggs's ability. I haven't seen Beckham play recently as he's a bit old for the Under 21s but everybody will be up for selection."