Newcastle United boss Rafa Benitez says Tim Krul's form in Holland last season convinced him to sell the goalkeeper.
Krul signed permanently with Brighton last week.
And Benitez revealed: "For five months we have watched him at AZ.
"We decided we would look at other options. That was a professional decision. I told him to find a new club to get playing time.
"We had enough keepers. I knew Rob Elliot had experience in the Premier League."