The keeper now has a full season under his belt at Old Trafford and believes his side can win everything possible this season with every player now back and ready to go.
"We are happy to see everyone back, because we are like a family. We have a very good relationship with each other. So yes, it's good. Very positive to have everyone back and hopefully we have everyone fit as well, as soon as possible, because we are hungry to start."
United have a lot of young talents who will rely on the likes of Onana for support and guidance this season.
"We have Kobbie (Mainoo), we have Garna (Alejandro Garnacho), we have Amad. I think that's something nice, and we will give them time. You have to know the Premier League is not easy, it is the biggest competition in the world, so this season might be difficult for them, but they are young, we will give them time.
"We, as leaders, have the responsibility and it doesn't matter what happens, we'll be there to support them in each situation."
Onana says the United side are used to big games and the young talents need freedom to show their talents this season.
As a leader within the squad, the Cameroonian sees his role mentoring the younger member of the squad on a par with his own responsibilities on the pitch, giving them the platform to succeed and shielding them in tougher times.
"We're used to playing for big clubs and we're used to playing in big games," Onana said. "We are here because this chalenge is huge, this is why they brought me and other important players here.”
"Also, young players, to be honest we were like them years ago. We give them experience, we take the responsibility when the team needs it and also, we give them freedom.”
"As the end of the day, football is about freedom and they have to be free. We are there to take all the bullets."
As a United player Onana thinks the side have to go all out and win everything this year and the keeper thinks they have what it takes to do that.
"For sure, 100 per cent. But it's not enough. Being a Manchester United player, you must win everything. You have to try and win everything. Each year you have to at least try to have one trophy.”
"Now big opportunties are coming, so we have to take the opportunity, because it's time to do everything on the pitch. When I see how we are training, when I see how my players are working hard, I'm very positive.”
"We want to win everything. That's what we came here for. We want to fight for the Premier League, we want to fight for the Europa League. We want to fight for the Carabao Cup, we want to fight for the FA Cup, because it's very important for us as a club."