Cazorla was reported last week as to favouring a move to the Emirates Stadium less than a year after he signed for Málaga, as the Andalusian club wrangle with financial problems.
Various outlets report the Spanish international, a member of the country's 2008 and 2012 European Championship-winning squads, will have a medical this week.
Last week Madrid sports daily Marca reported Arsenal were eyeing Sahin with a view to taking the midfielder on loan for the season.
The Gunners' interest is still believed to be on an initial loan move, as the former Borussia Dortmund seeks to play football on a regular basis again.
The Turkish international, 23, only joined the Primera Liga champions last year from the current German double-winners for £6m but was a peripheral figure under Mourinho.
He played just 10 times for Los Blancos in his debut season, scoring against Ponferradina in the Copa del Rey.
Sahin's move to north London should be welcomed by Arsenal fans concerned at Arsène Wenger's quotes last week that he did not require any more central midfielders.
Jack Wilshere has not played in over year and is scheduled to return in October, making Sahin's role much more pivotal if or when he does join the Gunners.
