Arsenal are one player short of being able to challenge for European success, says shareholder Alisher Usmanov.
Gunners boss Arsene Wenger has made only one signing this summer - goalkeeper Petr Cech from Chelsea.
However, they have been linked with a move for Real Madrid forward Karim Benzema ahead of their Premier League opener against West Ham on Sunday.
"Except for one position, I think Arsenal are ready to successfully fight for European cups," Usmanov told CNN.
Arsenal beat defending Premier League champions Chelsea in the Community Shield on Sunday, with Alex Oxlade-Chamberlain securing a 1-0 win.
Jose Mourinho's side are favourites to retain the title, but Arsenal - who finished 12 points behind Chelsea last season in third - have been tipped to pose a stronger challenge this time.
The Gunners have not won the league since 2004 and went almost a decade without a major trophy before winning the FA Cup in 2014.
Usmanov, Arsenal's second largest shareholder, believes it was the club's move to the Emirates Stadium in 2006 that hampered Wenger's ability to challenge for more trophies.
"Arsene had a very, very difficult position when club shareholders didn't want to put their money into constructing the new stadium," added Uzbek-born billionaire Usmanov, who is not on the club's board.
"Because of this Wenger lost five years, maybe the best of his career, without a trophy. In reality, 10 years.
"If I had the right, I would keep Arsene until he wants because until he cannot perform his activity as a manager, it is a gift for any club to have a coach like Arsene Wenger."