A family friend has revealed that the grief-stricken son of Formula 1 legend Michael Schumacher "finds it hard" to deal with his father's horror injuries.
The 49-year-old seven-time world champion Schumacher has been bedridden since December 2013 due to a skiing accident.
The motorsport icon was skiing in the exclusive French Alps resort of Mirabel when he suffered a traumatic brain injury after hitting his head on a rock.
A friend of his son, Mick, 19, who is an aspiring F1 driver currently competing in F3, has revealed he is "completely closed" about his dad's health
Nicklas Nielsen told Danish newspaper BT: "Mick does not say he is sad about his father. He just said sometimes that it is hard."
"I know him very well, also privately. He is a very quiet and calm guy. Very nice and welcoming and he talks to everyone."
Nielsen suggested he "may" be recovering but it was too difficult to know for sure.
Schumacher's family has been very private about the details of the ex-Ferrari star's condition.
Nielsen said Michael Schumacher's younger brother Ralf also doesn't talk about his sibling's health.
"It was completely closed and not talked about [by the Schumacher family]. I still do a little karting with Ralf Schumacher and his team and nobody talks about it," Nielsen said.
"It may be that Michael is on his way back and will only come out again when he is completely rehabilitated. But it's hard to say what's going on."
The sporting icon reportedly receives $200,000-a-week care at a special medical facility at his Lake Geneva home, adding up to costs which are now expected to have exceeded $35 million.
In 2016, his lawyer told a court that Schumacher "cannot walk" in response to speculation in German media about his condition, news.com.au reports.
Nielsen said despite the tragic family circumstances, rising star Mick is down to earth, and nothing like Red Bull F1 prodigy Max Verstappen, who he painted an unpleasant picture of.
"I know him [Mick] very well, also privately. He is a very quiet and calm guy. He is actually like everyone else," Nielsen said.
"Mick is a very nice and welcoming person, and he talks to everyone. He is not like Max Verstappen, who does not care about anything and anyone and just wants to go ahead for himself. Mick has been brought up properly and is a good boy."
Nielsen, also a professional racer who has competed alongside Mick, said father and son were always friendly towards everyone.
"Michael was with Mick around the tracks many times, so they were very close before the accident," Nielsen said. "They had a very professional approach to everything.
"Michael and Mick came in, walked around and said good morning to everyone and shook hands … They are just some nice people."
Last week, details of a heartbreaking letter from Schumacher's wife giving a rare update on his condition emerged.
Corinna Schumacher, 49, described her husband as a "fighter" in a note revealed nearly five years since his ski tragedy.
In the emotional letter, sent at an unknown time to a German musician, Corinna said: "I would like to sincerely thank you for your message and nice gift that will help us through this difficult time.
"It is good to receive so many kind wishes and other well-intentioned words — which is a great support for our family.
"We all know Michael is a fighter and will not give up."
It was written as a reply to Hamburg bandleader Sascha Herchenbach, who had sent the family a recording of a new song named Born To Fight. He had composed the track in the months after the tragic accident.
Herchenbach, 38, revealed the contents of the letter in an interview with German magazine Bunte last week.
He told the publication: "I had not expected to get an answer and was overwhelmed.
"The letter was handwritten and signed by Corinna on her stationery.
"She wrote that she was very thankful for the gift and it helped her and her family over this difficult time."
- additional reporting by new.com.au.