The 25-year-old signed a contract renewal after turning down the Red Devils’ offer during the closing days of the Premier League transfer window when Romelu Lukaku was also heading towards to Inter Milan.
Inaki was heavily linked with a move away from San Mames and reflecting on the speculations in August, the Spanish forward has revealed Man United wanted to sign him.
"I had contact from Manchester United but I cannot tell you who it was.
"My number one option has always been to stay at Athletic Club and to retire here.
"Joining Real Sociedad? No, I could never go there – 100 per cent."
Having made his debut for Los Leones in 2014, the versatile forward has gone on to score more than 45 goals in all competitions.
After three games in the new LaLiga season, William has scored once for Gaizka Garitano’s side who are yet to taste their first defeat when they travel to Mallorca on Friday.
Helping Bilbao to an eighth position on the league table last season, Inaki bulged the net 13 times in thirty-eight LaLiga games last term and has featured just once for the Spanish national team.
Remaining with the Spanish club, Inaki signed a nine-year extension with a €135million release clause.
With Manchester United failing to secure the services of the highly-rated Bilbao forward, United snapped up Daniel James from Swansea City instead.
