John Fleming, Walmart's chief merchandising officer, is leaving the company, effective Aug. 1, after 10 years with the retailer. His position will be handled temporarily by executive vice presidents Jack Sinclair and John Westling.

Sinclair will oversee food and health wellness categories, while Westling will handle general merchandise.

The staff adjustment comes on the heels of last week's promotion of Bill Simon to president and chief executive officer of Walmart U.S. stores, where he will report directly to Mike Duke, president and chief executive officer of Walmart. Simon replaces Walmart's vice chairman Eduardo Castro-Wright, who has been appointed to president and chief executive officer of global.com and global sourcing.