The rising Mexican star appears set to join Diego Reyes at the Portuguese giant next season.
Herrera was believed to be close to signing in January as the transfer window slammed shut, but the deal appears to be back on.
“I’ve given my word to Porto,” midfielder Herrera, 23, is quoted as saying.
“I know that they compare me to Moutinho,” he added in part of the interview.
Reports in the Mexican press suggest that a few loose ends still need to be tied up between the clubs for the player to officially make the move.
If “El Zorrillo” (The Skunk) does sign for the Portuguese giants, he will join fellow Olympic and national team player Diego Reyes, who announced his transfer from Club America to Porto over the past winter.
The Portuguese club is well known for buying Latin American talents, having signed Radamel Falcao, Jackson Martinez, Hulk, James Rodriguez and Nicolas Otamendi in recent years.
Herrera has had a mixed season this Clausura, opening up with a stunning solo goal in the first round of matches against Atlante, but not having the impact he would’ve like through the season, with Pachuca slipping from the playoff reckoning.