"It's been tough for them," he said when asked how his family and friends have handled the accusations.
"It's been pretty emotional too. Just seeing them get ambushed and I guess, that sort of thing was pretty disappointing and hard to watch and listen to them.
"Thay're strong. They're getting through it and we'll get through this."
Hayne said on Wednesday said he is not able to address the allegations and repeatedly told reporters they would have to speak to his lawyers over their questions about the ongoing case.
"If youse want to talk about football I'm more than happy," he said.
"I think youse need to understand and make it very clear that the situation that's going on, I can't talk about it. So youse can ask whatever it is youse want to ask, but I'm just going to avoid it and deflect it and talk about my lawyers.
"You'll have to speak to my lawyers."
At the end of the press conference, Hayne's lawyers released a statement in which they stated Hayne has found the accusation "personally distressing".
The statement, issued by Madison Marcus Law Firm, also declared Hayne is yet to receive any formal documentation associated with the civil suit filed in the Santa Clara County court.
"The last week or so have been personally distressing for not only me, but my family and friends, as civil proceedings making serious allegations have been publicly aired, and in certain media have followed me on a personal pre-planned trip to the other side of the world," Hayne said in a statement.
"I was not given any notice of these proceedings prior to any media reports.
"I confirm that I unequivocally and vehemently deny the allegations made against me and I will be vigorously defending the matter. As everyone should understand, I cannot publicly discuss anything relating to this matter as it is now the subject of legal proceedings in the United States.
"I'd like to thank all the family, friends and fans who have both privately and publicly sent messages of support."
The Eels' first training session of 2018 was the first time Hayne has worn Parramatta's blue and gold since he left the club to pursue a career in the NFL at the end of 2014.
It has been just over a month since Hayne walked out on the Gold Coast Titans to return to Parramatta, but his Eels defection was not the biggest question mark hanging over the 29-year-old when he faced the press at Parramatta Stadium.
The NSW State of Origin star has denied in a written statement claims from a US civil suit he raped a 25-year-old woman in 2015 while playing for the San Francisco 49ers.
The woman, identified only as "Ms V" went for a drink at a bar with friends after attending the 49ers' 24-14 loss to the Cincinatti Bengals on December 20, 2015, at Levi's Stadium near San Jose, according to court documents.
Court documents submitted in the civil suit against Hayne allege that in the early hours of Monday, December 21, 2015 "despite having minimal interaction that night [Hayne] took the now heavily intoxicated [woman] back to his home in San Jose via Uber".
It was in his apartment the alleged incident took place with the woman who says she had never had sexual intercourse previously.
The documents say she felt pain, and the following morning woke up among bloodied sheets.
She then took "an undergarment" because she allegedly felt people would not believe the incident had taken place, and for police to test.
The civil suit, filed in the Santa Clary County court, includes claims of sexual battery, battery, negligence, gender violence and intentional infliction of emotional distress against Hayne.
Through his legal representatives, Hayne has previously unequivocally and vehemently denied the allegations.
In May 2016, the young woman reported the alleged assault to San Jose police.
The District Attorney's office informed the young woman that "there was not enough evidence to prove the crime of rape beyond a reasonable doubt".
The NRL released a statement in December to announce it is unlikely to stand Hayne down during the civil suit.
The Eels have also said publicly they will monitor the situation, but have not stood their star-signing down dfrom any duties.
The two-time Dally M medallist first completed a time trial run and ran laps at the Eels' training base in front of a throng of cameras and awaiting media in scenes reminiscent of Parramatta's scandal-plagued 2016 season.
Regardless, the media circus surrounding Hayne's every movement will be precisely what low-key coach Brad Arthur would have wanted to avoid when he signed the high-profile player.
The Eels have claimed they were unaware of the allegations when they signed him last month.
Hayne spoke to local investigators after the woman went to the police in May 2016, but the case was rejected by the Santa Clara County District Attorney's Office in October of that year due to a lack of evidence.
The woman is now pursuing Hayne on claims of sexual battery, gender violence, infliction of emotional distress and negligence. Hayne was signed in August 2016 by the then-NRL-owned Titans, who have also claimed they were unaware of the investigation at the time.
— with AAP