Anita, who moved from Ajax in 2012, is familiar with de Jong’s talents from their time together in the Netherlands as both progressed through the club’s famed youth system.
De Jong made the switch to Tyneside this summer for a fee reported to be in the region of £6million and Alan Pardew has already named him as vice-captain ahead of the new season.
The Dutch international made just short of 250 appearances in all competitions from Ajax – finding the net on 78 occasions – and Anita has backed him to adapt to life in England.
"Siem can be a great player in the Premier League. I was excited when I heard Newcastle had signed him because I have known him since I was little," he told The Sun.
"We played for six years together at Ajax and are good friends, so it was very nice for me that he has come."
De Jong has already impressed in pre-season this summer, finding the net in Newcastle’s 2-1 defeat at Oldham as well as their 4-0 win over Sydney.
Anita added: "He is a very technical player. He always finds holes to be free in and he links up very well with the striker. He has scored goals easily so far and I hope he can keep that up in the league.
"The fans should be excited by his arrival."