Herrera was speaking as he and several other United stars including captain Wayne Rooney, star goalkeeper David de Gea and record signing Angel di Maria took part in a foundation event at a local school.
The Spaniard has come back from the abyss in recent weeks to score three goals in three successive games and has already become an incredibly popular figure with supporters, scoring five goals since his arrival last summer.
Speaking about some of the younger players at United, Herrera said: “I didn’t realise how good the academy was. Januzaj and Pereira are going to be very important players.”
Januzaj’s emergence as a teenager last season was one of the bright points of David Moyes’ ten months in charge at Old Trafford but under Louis van Gaal the 20-year-old has taken a back seat role, despite regular minutes in the last month or so.
Pereira is out of contract this summer and United will be keen to avoid a repeat of the situation with Paul Pogba from 2012, especially given Pereira’s now made his first team debut and is continuing to impress with the U21s side.