"I think that Manchester United, since I was young - and I'm not just saying this because I'm here, I'm an honest guy and I never lie - I think it's the biggest club in England. That's what I think.
"There are lots of big clubs, and having played for Arsenal, they are also one of them. It's a huge club and I was there.
"But coming here, looking at the badge, I think United have to win everything because it's such a big club. The club crest says it all."
The diminutive attacker gave up life in north London to make the switch to the Theatre of Dreams in January, as Henrikh Mkhitaryan went in the opposite direction in a swap deal.
Sanchez also spoke about Arsenal and the opportunity to join United, "I left Arsenal because I wanted to develop and learn as a player and get to experience a new club. Manchester United are a huge club on the global stage. I came here to win everything. Otherwise, I wouldn't have come here."
Sanchez opened his goalscoring account as United beat Huddersfield 2-0 at home in the league, with the former Gunner missing a penalty, only to swoop to tuck away the rebound.
United are out of the title race with Manchester City streets ahead in the Premier League, but opportunity knocks in the FA Cup and UEFA Champions League, as manager Jose Mourinho demands silverware from his expensive squad.