Nemanja Matic has told Sky Sports that Manchester United are one of the three biggest clubs in the world after swapping Chelsea for Old Trafford in a £35 million move this summer.
Matic, who also spent three years with Benfica, won the Premier League title twice at Stamford Bridge, once under United boss Jose Mourinho in 2014-15 and again under Antonio Conte last season.
He made his full debut for United in Sunday's 4-0 win at home to West Ham United, and earned the man-of-the-match award.
"Definitely, everyone knows what Manchester United is about," he said. "When you say Manchester United, it is different. Also Chelsea is a big club, Benfica are the biggest club in Portugal. But Manchester is Manchester.
"When I came here for the first day, I could feel that the people at the club help you every day if you need something and supporters are very important for this club.
"After every training session, they are waiting for us outside the training ground to take pictures, to give a signature so I think the club is one of the biggest in the world. Maybe you have two or three clubs similar to United, but Manchester is one of the biggest clubs in the world for sure."
Meanwhile, Chris Smalling believes United will benefit from a settled dressing room this season while some of their rivals are in turmoil.
Mourinho said in his programme notes ahead of the 4-0 win over West Ham he had "never worked with a group he liked as much."
It is in contrast to Chelsea, Arsenal, Liverpool and Tottenham, who have seen controversies surrounding the future of Diego Costa, Alexis Sanchez, Philippe Coutinho and Danny Rose blight their summers.
"It's hard to be able to have 25 players that all get along but I've found in the dressing room everybody is getting on, everyone's joking, we've got music playing and everyone is laughing and joking about," Smalling told The Metro.
"I hear a lot of stories from other clubs and there's a lot more people that don't get on than us so I think we're very blessed to have the changing room that we have."
Smalling watched from the bench as Mourinho opted for Eric Bailly and Phil Jones as his centre-back pairing against West Ham. New signing Victor Lindelof was omitted from the squad as he adapts to life in the Premier League, while Marcos Rojo is still recovering from a knee ligament injury.
Smalling, though, is hopeful of getting enough games to secure a place in England's squad for next summer's World Cup in Russia.
"I think it's a case of staying injury free," he added. "I think last year I had a couple of long injuries that sort of ruined that momentum.
"But I've started this season fit and hopefully get as many games as I can and go into a summer which is also a big summer as well so it's a big year ahead for club and country."