Benitez failed to sign Barry last summer as the Liverpool board refused to splash out £18million on the England midfielder.
Aston Villa boss Martin O’Neill said: “Gareth was true to his word that he would stay in January. If we keep the momentum going, who knows? But if we don’t qualify for Europe, things will be in the balance.
“Having given this season, I don’t think anyone would begrudge him the opportunity to move.”