The 24-year-old midfielder moved to Old Trafford in a £29million deal last month - nine months after a proposed switch had fallen through on transfer deadline day.
In his first press conference since Herrera's departure, Urrutia said: "For us, Ander Herrera was a player we expected to stay at the club.
"According to what he said, Ander was delighted to be here and his only aspiration was to stay here."
Athletic have also announced that midfielder Iker Muniain had signed a two-year contract extension, which sees his buy-out clause raised from £30m to £35.9m.
"We've reached an agreement with Iker, which is good news," Urrutia said. "We have had three exceptional cases recently. If it became a trend, it would be dangerous.
"Our players' maximum aspiration has to be to stay at Athletic. We are looking forward to an exciting year, which starts on Monday."