Betis, now coached by Manuel Pellegrini, tried to sign Lopez in the 2016-17 season when he left Napoli.
Lopez passed a medical with the Andaulsian club before Espanyol interfered and re-signed their homegrown star.
He is one of Espanyol’s top five earners and knowing this is his last chance to get a good contract, isn’t willing to lower his salary to stay at the club.
Having not qualified for Europe and facing a summer of austerity, Betis see Lopez as a good signing.
Lopez will only command a small transfer fee, certainly much less than the €5.5m that Napoli paid Espanyol for him in 2016.
In his two spells for the Catalan club, Lopez has made 181 appearances, scoring 11 goals.