He said: "Juventus have expressed an interest in acquiring Xabi. The clubs have spoken and they will speak again.
"But it's down to Liverpool to decide whether they want to sell the player or not. From my part I am waiting to see what happens."
Alonso was one of Benitez's first signings when he took over as manager four years ago, arriving for £10.5million from Real Sociedad.
The 26-year-old has played 163 games for the club and scored 14 goals but featured little towards the end of the season.