Arsenal minority owner Alisher Usmanov has warned there is a "real risk" that Arsene Wenger's legacy could be tarnished if he does not receive the right support after agreeing to prolong his 21-year stint in North London.

Months of uncertainty and unhelpful speculation finally came to an end on Tuesday (31 May), when the FA Cup holders finally offered public confirmation that their long-serving boss had put pen to paper on a two-year contract extension.

Usmanov, who currently owns a 30% stake in Arsenal but does not sit on the board, claimed to be content to see Wenger defy his critics and extend his tenure even further.

However, the Uzbek-born Russian steel magnate also increased the pressure on under fire majority shareholder Stan Kroenke to give the manager the backing that he needs to restore success after a disappointing season in which the club missed out on Champions League qualification for the first time in 20 years.

"I am pleased Arsene Wenger will continue to manage Arsenal for the next two years - he is one of the best coaches in Europe," Usmanov said in a statement, as per Sky Sports. "What is now of paramount importance is that he receives the full support of the board and the majority shareholder.

"He has a great opportunity to deliver the success that the fans deserve and the legacy his long contribution merits. However, without the right support there remains a real risk his legacy will be tarnished. If the support is not forthcoming we stand ready to step in and do everything we can to deliver success on and off the field."

Usmanov has long been an outspoken critic of Kroenke's approach and reports from the Financial Times earlier this month claimed that he had made a $1.3bn (£1bn) offer to buyout the American. However, Kroenke Sports & Entertainment (KSE) subsequently said in a statement given to the London Stock Exchange that their shares "are not and never have been" for sale.

They insisted: "KSE is a committed, long term investor in Arsenal and will remain so."