Fellaini followed Moyes from Everton to Old Trafford two seasons ago when the Scot was chosen to replace Sir Alex Ferguson.
Things did not work out for Moyes though and he was sacked last April, just 10 months into a six-year contract.
Fellaini grew close to Moyes during their time together at Goodison Park and Old Trafford so t he big Belgian was overcome with emotion on the day the Glaswegian was shown the door
Fellaini, speaking to So Foot magazine, recalled the day that United sacked Moyes after 24 hours of intense speculation that he would be relieved of his duties.
"When he left I was sad," the United midfielder said.
"We had heard things on the radio and TV (about Moyes leaving)
It was after a defeat to Everton.
"I did not know if it was true or not
Then I arrived the next day at the (training ground) canteen, and I saw him in his suit, rather than his tracksuit
I told myself: 'This is the end.'
"It was weird
After I had eaten, he summoned to his office and he told me the news
This is football.
"There were tears
This is normal
I am a human being
I worked with him for six years.
"He was not a second father, but almost
He helped me a lot".
Like Moyes, Fellaini struggled to deal with the step up from Everton to United last season.
United spent £27.5million on Fellaini but he failed to score a goal in his first year at the club.
The 27-year-old has hit back at suggestions that he was to blame for United's dour season under Moyes, which ended with the club finishing in seventh place.
"During my first season at Manchester, the team was not performing and I was the scapegoat," Fellaini said.
"Everything was Fellaini's fault.
"If you pay attention to all this (criticism), you sink.
"It destroyed me on every side."
Fellaini was expected to leave Old Trafford last summer, but he has excelled at the club after being given a second chance by Moyes' successor Louis van Gaal.
"I knew it was going to be difficult when he (Van Gaal) arrived because I was the scapegoat last season
So I told myself I had nothing to lose," Fellaini said.
"I had one chat with him at the start of the season on my return from the World Cup
He told me there were a lot of players in my position and it was up to me to prove myself.
"After a few training sessions, I felt things were going well
He tested me
He put me up against players who could make things difficult for me, little, lively ones.
"Either one-on-one or in groups of four
He observed me in these games and watched the videos, too".
Source : PA
Source: PA