San Francisco-based Zynga (NASDAQ:ZNGA) is shaking up its management ranks this week.

In a filing with the SEC this morning, it announced that two executives, Steve Chiang, previously president of Zynga's Games division, and Barry Cottle, previously the company's Chief Revenue Officer, have "transitioned" to "managing certain game teams and operations," and so, effective Aug. 13, are no longer holding their former posts. Zynga said Chiang and Cottle now have the title of executive vice president, Games, and have "transitioned responsibility for other aspects of their prior positions to other employees in the Company."

Zynga also reported that Chief Operating Officer David Ko has resigned from the company, effective Aug. 16. Upon his departure at the end of this week, Ko will be paid severance of four months' base salary, plus one week's salary for each year of employment, plus an additional cash payment of $562,500, plus enough cash to pay for four months' worth of health insurance under COBRA, according to the SEC filing.

Ko had worked at Zynga since 2010, implying that his salary-based severance benefits will amount to approximately $142,500, resulting in a total severance payout approximately $705,000, plus the insurance benefits.

According to a company blog post yesterday, Cadir Lee and Colleen McCreary are also leaving the company to pursue other interests. According to TechCrunch, Lee is chief technology officer and McCreary is chief people officer.

CEO Don Mattrick said in the post, which was sent to all employees: "I have been working with our leaders to review different parts of our business in order to develop a set of operating principles to help reset the company. We are now calibrating against the market opportunity and developing detailed plans to achieve topline growth and improve profitability in the future. ... We are taking layers out of the executive rank to get senior leaders closer to important product initiatives."