Pearson has confirmed the Tigers have tabled a bid for the Spaniard, who made 12 appearances for them during a three-month loan spell last season, but the two clubs cannot agree on a valuation.
Pearson, whose side launch the new Championship season at home to Blackpool on Friday night, told the Hull Daily Mail: "I never rule anything in or out but I would say it's unlikely.
"Ayala is a target and we've put a bid in. The clubs are in discussion and we'll see where it takes us.
"As always the criteria of how you add to your squad is governed by finances but we'll always try and bring in the best players that are available to us."
Source: Team Talk
Source: Team Talk