The Barcelona centre-back, 32, stepped down from Spain duty following the 2018 World Cup after fracturing his relationship with many fans over his support for Catalunya’s independence bid.
However, in an interview with Cadena SER, Pique hinted that he could reverse that decision.
"You never know, you never know," he said.
"In life you don't have to discard anything. I've never ruled out anything in life. It can happen. Why not? I don't like to close the doors on anything."
With Olympic teams only allowed three players aged over 23, Pique's recall would be far from guaranteed – especially after Spain captain Sergio Ramos' declaration that he will not turn down a spot in Tokyo.
Spain are aiming for a first gold medal at the Olympics since triumphing on home soil in 1992.
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