Usmanov owns 29.35 per cent of the club but has sent a letter to all small shareholders offering to buy theirs at £14,000 each - significantly more than Kroenke is offering.
If Usmanov increases his stake to more than 30 per cent by buying another 405 shares he would be subject to the Premier League's Owners and Directors Test, their updated Fit and Proper Persons Test.
Assuming he passes, then Usmanov will increase his demands to have a seat on the board - something that Kroenke, who owns 66.7 per cent of the club, has always refused.
But crucially, the American would not be able to prevent Usmanov from inspecting the club's accounts, which he could then use to increase pressure on the board.
And the situation is set to come to a head around the club's AGM on October 27, when Kroenke is likely to be in London and talk to supporters and shareholders.
Usmanov - rated as the 35th richest person in the world with £12.4billion - has consistently said he would provide more money for under-fire manager Arsene Wenger, whereas Kroenke has supported the club's self-sustainable model.
Yet it is far from clear where Usmanov - who made a counter-offer when Kroenke completed his takeover of the club in May - will be able to purchase his shares.
One intriguing avenue is that around 200 shareholders are thought to be deceased and the future of their investment remains uncertain. Another, is to buy shares from the Arsenal Supporters Trust's celebrated Fanshare scheme, yet they are seeking to increase their stake rather than sell.
Fanshare's 1900 members own approximately 70 shares, worth around £800,000 but have been told neither Usmanov nor Kroenke are willing to sell to them unless the other major shareholder does.
But the two competing side's valuation of Arsenal differs, with 64-year-old Kroenke, who last month gave Wenger his full support, buying his shares at £11,750 each. That values the club at around £731m, whereas Usmanov's value increases that to £871m.
Therefore, Kroenke would stand to make a significant profit if he decided to sell all of his stake to Usmanov, although the chances of that happening are slim.
And rather, Usmanov's latest move in the game of chess surrounding events at the Emirates Stadium is likely to have been done with an eye on viewing the books at Arsenal.
Under Premier League rules the club's accounts have to be signed off by all directors - and it is thought that Usmanov has spotted a loophole as he would therefore be able to demand to see that financial information if he owns more than 30 per cent. The club last month announced football turnover of £225.4m for the year up to 31 May 2011 _a rise of just one per cent on the previous season - while the wage bill increased to £124.4m, which was up 12.4 per cent.
And they face the prospect of failing to qualify for the Champions League after their horrific start to the season, which has seen the club take just seven points from seven games, including an 8-2 defeat at Manchester United.
Chief executive Ivan Gazidis said last week the club's business plan was not based on securing Champions League football and that Arsenal would 'remain competitive' if they did not make the top four.
Yet that does not address the fact that Robin van Persie, Theo Walcott and Thomas Vermaelen are all out of contract in the summer of 2013 and could be sold at the end of this season if they do not agree new deals.
That would be a huge blow to the club, especially as Cesc Fabregas and Samir Nasri departed in the summer just gone, for Barcelona and Manchester City respectively

From Evening Standard.
Wow. The wage bill is higher than I thought! Unbelievable. It's GONE UP to over £120 mil!!! I know we got rid of a few people but we've brought in a few too. That is truly unbelievable stuff I have just read, and makes a mockery of 'self sustainability'!!!!
Fucking farcical. Read those figures again. Then ask yourself how a club that manages to concede 4 and lose to Steve Kean managed Blackburn and ship EIGHT at OT, can possibly justify that wage bill, or a 6.5% increase.
When Gazidis/Kroenke next insult you lot at an AGM, don't let them get away with it. Don't let 'self-sustainability' and 'cannot compete with Citeh' be used legitimately because Arsenal's wage bill is only lower than Man United's by just over £15 mil!!!!!

What Gazidis, Wenger and Kroenke donot understand, is that this Holy Trinity of C**s, through their sheer arrogant incompetence have actually helped Usmanov to become more popular than he ever could have dreamed of!!!!
A combination of Wenger's rank management, with the lack of pressure at board level, and Gazidis's complete cluelessness about European football have increased Usmanov's legend.
If you think a man as rich as Usmanov would tolerate the shite we are seeing now, thin again. Remember, Kroenke has borrowed plenty and the money where he's from comes from his wife mainly.
Usmanov has more cash than Abramovich.
Two billionaires on the board but Arsenal 'cannot compete with ManYoo (the Glazers up to their arses in debt) and Chelsea'.
Comical.