Erasmus spent the past season with United following a loan move from Feyenoord, with whom he has a three-year contract.
The Amajita star will start pre-season training with the Dutch side on Saturday, taking with him a reputation as a promising footballer after an impressive start to his professional career with Supersport United.
The Port Elizabeth-born star, who turns 18 next Tuesday, revealed his excitement to KickOff.com.
“I’m leaving for Holland tonight. I’m quite excited you know. I’m going to one of the biggest clubs in Holland. Obviously, it’s going to be tough for me to just break into the first team, but I’m up for the challenge.
“I’m sad to be leaving my family and friends, but it’s something that I have to do. I must move on with my life and my career.”
Erasmus spent some time at the club before returning to South Africa to join SuperSport United on a loan deal, and told KickOff.com about the huge gaps in professionalism.
“It’s much more professional over there. There is a kit room, where you get your shorts, jerseys and socks, even your boots are cleaned for you, that doesn’t happen in South Africa.
“Holland is quite an adjustment. The people keep to themselves, they stay indoors and the weather is not that good, but I am confident of making it.”