Sawyer was previously night editor at London's Evening Standard newspaper, which is published by Associated Newspapers.
Associated acquired 60% of Catchpole Communications, the management team of 7Days, for US$7.2 million last October.
Following the deal, the title increased frequency to seven days a week. Plans are also afoot to launch new editions and grow circulation.
In the past few months 7Days has been criticised for publishing stories that were not consistent with the religious, cultural, political and moral values of the UAE.
In a statement, 7Days said that Metcalf "will take control of web and new product development outside the UAE for Catchpole Communications."