West Ham's first home game of the 2017-18 Premier League season will come in September after the fixtures with Southampton were reversed due to the World Athletics Championships taking place at the London Stadium.
West Ham had been scheduled to host Southampton on Saturday, August 19, but the athletics showpiece finishes less than a week earlier, running from August 4 to August 13, and it will take time to return the stadium to 'football mode'.
The reversal of the fixtures means St Mary's will host the August match and Saints are scheduled to return to West Ham on Saturday, March 31, 2018.
West Ham had informed supporters of the change when the fixtures were published last week and it was confirmed on Monday.
It means the Hammers' first three games - against Manchester United, Southampton and Newcastle - are away, with Huddersfield scheduled to be the first visitors following the international break on Saturday, September 9.