The man who helped Pat Cash to a Wimbledon crown says grief is "massively amplified" for professional athletes after Nick Kyrgios' shock French Open exit.
Kyrgios pointed to the death of his grandfather in April after his second round capitulation against South African world No. 56 Kevin Anderson on Friday morning.
Former Olympics sport psychologist Jeff Bond said people grieve differently, but being under an immense media spotlight dramatically affects the process.
Kyrgios was cruising before his serve failed him in the second set and the Canberran went on to lose 5-7 6-4 6-1 6-2, dropping the final two sets in just over an hour.
"After my grandpa passing, I just lost a lot of motivation to do anything, really," Kyrgios said post match.
"When I was back home, it was tough. I mean, I can't talk about it. I can't."
Bond said it would have been tough for grief-striken Kyrgios to produce his best tennis but added he understands skeptics questioning Australia's best player.
"It's very hard to predict how people will process the event that causes the grief, some choose not to address it or can't at the time, so they internalise the grief and it pops out later," Bond said.
"Usually, like most traumatic memories, grief seems to pop up when we least want it to and when we're not in such a great space.
"The skeptics would say Nick Kyrgios won the first round in great style and looked terrific and then if you look a the scoreline in the second round and didn't know any better you'd say he gave up.
"The 6-1 6-2 on a sliding scale usually indicates they don't want to be out there. Skeptics say why blame the passing of your grandfather a few months ago when it didn't it affect you in the first round.
"Is it is just excuse making or is it genuine? It's very hard to tell."
Anderson took advantage of Kyrgios' meltdown and secured his second win in as many meetings with the world No.19.
"I was in his head after winning that second set," Anderson said.
"He was struggling with his own battles, I didn't give him a way to get back in the match. So it's something that I knew I needed to do, and I thought I was able to execute that very well today."
Bond said in the professional sporting ranks, tennis players are among the most vulnerable to self implode during play.
"One of the reasons I love working with tennis players is because there is no place to hide, you can make all the excuses in the world but at the end of the day you've lost and it's your fault," Bond said.
"Your ego is out there for your opponent to step on and they love to step on it, and I'm sure a lot of players out there would love to step on Nick's.
"Players use excuses because their ego has just been smashed. It is true many athletes look to blame external circumstances when things don't go well - injury, weather, umpires, crowd.
"It's a protection of the ego but who knows with Nick Kyrgios, he's a conundrum for most people who try to analyse behaviour in sport."
Bond worked with Cash at the height of his powers in the 1980s and said there were similarities between the former world No. 4 and Kyrgios.
"Patrick's behaviour was misinterpreted by many people on many occasions. He came across as the brash spoilt brat extrovert, but when I met him he turned out to be the exact opposite," Bond said.
"It's very difficult looking from the outside to understand some of those inner processes and I don't think anyone knows Nick Kyrgios other than his parents and family.
"I'm sure sometimes his behaviour even bewilders them as it does the rest of us. I would say Pat and Nick are similar to the extent we don't understand these complex individuals."