The former Germany international branded the current European champions as fortunate, though he clarified that good teams always find ways to win
La Roja are on course for a third consecutive major title after beating Portugal 4-2 on penalties, to book a date against Italy in the final on Sunday.
Schuster, who played for both Barcelona and Real Madrid in the 1980s, believes that while Vicente del Bosque's side have been rather fortuitous of late, it is a necessary ingredient for victory.
"Spain have been very lucky. If you are not, you do not win ever. It is essential to get lucky and in previous competitions, Spain did not have any luck." the former Germany international told Onda Cero.
"[Italy] defend very well, [Andrea] Pirlo organises everything and directs the ball where he wants. They also have a good bench and do their job."
"However, no team can take ball possession off Spain."
Sunday's Euro 2012 final at the Olympic Stadium in Kiev kicks off at 20:45CET.