"That's why I'm a bit scared for the English coming over here. The way the Super 14 is being played and the way the All Blacks play, I just don't think they will be able to keep up."
The 24-year-old, back in New Zealand for a holiday after Sale failed to reach the Premiership play-offs, also hinted that next season could be his last with the Sharks, saying he missed his Blues and All Blacks team-mates and his daughter Astyn.
"I have only got one more season and I could be back. Hopefully if it goes to plan I will be back (in New Zealand)," he told TV3.
"I don't know what's going to be thrown at me in the next seven or eight months. I haven't talked to the (New Zealand Rugby Union) about it.
"But I have got my little girl over here and it's hard being away from her so she would be a big draw card for me coming back."
McAlister is also doing his best to put last year's World Cup defeat to France behind him.
"It was heartbreaking, not only for the players and New Zealand rugby but for the New Zealand public it was hard to take.
"But I've moved on. You learn from your mistakes and experiences and hopefully become a better player and a better person for it."