Schappert had joined the social gaming company in May 2011, after having served as COO of Electronic Arts (EA). It is not believed that a recent EA lawsuit against Zynga played any role in Schappert’s resignation.

“We can confirm that John Schappert has left Zynga and its Board of Directors effective immediately,” Zynga CEO Mark Pincus said in an emailed statement. “John has made significant contributions to the games industry throughout his career and we appreciate all that he has done for Zynga. John leaves as a friend of the company and we wish him all the best.”

As part of the July reorganization, both David Ko (head of mobile) and Steve Chiang (head of game dev) began reporting directly to Pincus, rather than to Schappert. The move came amid Zynga’s inability to reverse downward pressure on its stock price, which closed trading today at just $2.95 per share.

A source familiar with the situation says that there are no immediate plans to recruit a new COO.

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