West Ham United have been scouting Rio Ave, a mid table Portuguese team, for a year. In February 2016, West Ham sent an official to watch the club, and their visits have been regular since.
Almost every month, West Ham have had someone watch Rio Ave matches, and that continued on Monday as the club faced Feirense. Portuguese newspaper A Bola reports that West Ham had an official at the match, along with scouts from Everton and Brighton.
There’s every chance it’s neither of the above, but it would appear West Ham certainly have their eye on someone. Scouting Rio Ave continually isn’t like sending someone to watch Benfica, Sporting, Porto or Braga, where the talent is plenty.