However, the Catalan side had to play the whole second half with 10 men after Pique picked up a second yellow card for what referee Willie Collum deemed to be a deliberate handball inside the Olympiacos box.
Valverde has claimed that Pique's decision to go for a Gerard Deulofeu cross with his hand was purely 'instinctive'.
"Pique? I haven't seen the replays, but I'd imagine it was all instinct, with the goal so close to him," Valverde told Football Espana.
Barcelona will return to La Liga action this weekend with a home game against basement side Malaga.