The Belgium international found himself heading towards the free agent pool 18 months ago as his contract at Old Trafford ran down.
A move elsewhere was expected, but the trust shown in him by Jose Mourinho convinced the 31-year-old to commit to fresh terms.
A new two-year deal was agreed, with Fellaini snubbing interest from afar in favour of extending his association with the Red Devils.
Among those to miss out on his signature were Ligue 1 champions PSG.
Speaking to Telefoot, Fellaini said during a yes or no quiz: “Could I have signed for PSG last summer? Yes.
“Would I have liked to play for PSG? Yes.
“Was it Thomas Tuchel who did not want me to come? No.”
Having opted against heading to the French capital, Fellaini ended up spending just six more months in Manchester before eventually moving on.
The departure of Mourinho from the United dugout in December saw him slip down the pecking order under Ole Gunnar Solskjaer and he was allowed to link up with Chinese outfit Shandong Luneng during the winter window.
Explaining that decision, Fellaini said: “I think it was the right time to leave.
“It had been ten-and-a-half years since I arrived in England. I had beautiful seasons. Now I wanted a new challenge and a new adventure.”
Fellaini is now an interested observer of the goings-on at Old Trafford, with United enjoying a welcome upturn in form under Solskjaer.
They have collected 10 wins from an 11-game unbeaten run with an interim boss at the helm and have restored belief heading into a testing sequence of fixtures.
The first of those is set to see them face PSG on Tuesday in the first leg of a heavyweight Champions League last-16 encounter.
Fellaini said of that contest: “I think Manchester United are the favourites.
“With the confidence, they have at the moment, and how they play, I think they are favourites. But it's a Champions League match, in the round of 16, so it'll be 50-50.
“PSG have great players but they have two or three players injured. I think Manchester United have the advantage.”
United’s cause has been aided by untimely injuries to PSG attacking stars Neymar and Edinson Cavani, with both men expected to miss out on a European trip to England.