Arsenal fullback Bellerin was outstanding for Betis while on-loan last season and is eager to return.
"Yesterday when I left the sports city, people asked me if Héctor was going to come and they offered to put in to raise money with a piggy bank," said Betis striker Borja Iglesias.
"He has shaved off his mustache and is not going to grow it until he returns to Betis. He really wants to return."
Also, when asked about Joaquín Sánchez, who turned 41 this week, Borja added: "He's a guy who gives us a lot and I hope he never leaves.
"He still has legs and lungs. If he feels good... we'll see what happens, in the end I hope something very, very big happens to him because he deserves it."