Herrera, who started his senior career with Zaragoza, is expected to be one of 33 players - including Atletico Madrid midfielder Gabi - to be summoned in a case that could last up to six months.
After the emergence of fresh claims this week, however, the 28-year-old has stressed that he was in no way part of any wrongdoing.
"As I stated back in 2014 when this issue was raised, I have never had and will never have anything to do with manipulating match results," he said in a statement.
"If I am ever called to testify in a judicial hearing, I will be delighted to attend as my conscience is totally clear. I love football and I believe in fair play, both on and off the pitch."
Herrera left Zaragoza for Athletic Bilbao in 2011, spending three years with the Basque outfit before joining Man United.