Fabregas – who ended an eight-year stint at Arsenal in 2011 to link up with Barcelona – was shocked by Real Madrid's decision to sell Ozil on transfer deadline day.
Ozil signed a long-term contract at Arsenal after the two clubs agreed on a reported fee worth £42.5 million, as Real brought in Welsh star Gareth Bale for a world-record transfer fee a day earlier.
The Germany international was a key member of Real Madrid's squad though, and regularly linked well with Cristiano Ronaldo, and several members of Carlo Ancelotti's team have voiced their displeasure at Ozil's sale.
"I was really surprised by Ozil's departure," Fabregas told Spanish radio station Cadena Cope.
"He seemed to me the second-best player at Madrid, after Cristiano (Ronaldo)."
And Fabregas, a former Arsenal captain and favourite, has tipped Ozil to be a hit at the Emirates Stadium.
"He'll be great for Arsenal," he continued.
Ozil, who began his career at Schalke, joined Real Madrid in 2010 from Werder Bremen.
He made 143 appearances for Real Madrid, scoring 24 goals in the process.
