All Whites captain Winston Reid has suffered a head knock during West Ham's 3-0 Premier League loss at home to Brighton and Hove Albion.
Heading into injury time, Reid jumped to attempt a header, but instead collided with Brighton's Izzy Brown, causing the 29-year-old to drop to the turf and clutch at his head.
Although Reid was able to play out the remaining three minutes of the match, his head collision could put him in doubt for next month's inter-continental play-off against Peru.
West Ham are yet to confirm the severity of the injury, however, and whether Reid joins fellow defender Andrew Durante on the injury list remains to be seen.
Meanwhile, Glenn Murray scored a brace as Brighton recorded their first-ever EPL away win and first in the top flight since 1983.