De Jong previously told some around the sport that he had been at Everink's home on March 3, and was perhaps the last one to see him alive. But Thursday's news seemed to come as a complete shock.
"I have no words for it," Haase told Dutch Quote magazine about the murder earlier this month. "He was going to start a business again, and would soon have been travelling with another tennis player. No, I thought he had found his peace, so I had no indications that he was being threatened or anything like that."
De Jong, 29, is a former journeyman player on the Challenger circuit who switched to coaching a couple of years ago, and has been working with the world No 59 Robin Haase since the end of 2014.
Everink had previously made headlines in Holland after being involved in a fight with former heavyweight kickboxing champion Badr Hari at a dance music festival in Amsterdam which left him with a shattered ankle.
According to the Telegraph, he had not worked since the injury but was beginning to get his life back on track.
-News.com.au
