Last summer, West Ham set up links in Portugal and were trying to sign several players from the Primeira Liga (Sky Sports News).
The Hammers captured Xande Silva and have since signed Mesaque Dju. This is clearly a market that West Ham are hoping to explore in the coming summer.
Here are five Primeira Liga players that Manuel Pellegrini should target this summer.
Centre-back Ruben Dias is regarded as one of the best young defenders in Europe. The 21-year-old has already played over 70 games for Benfica, despite his age.
The 6-cap Portugal international has the full package and all the attributes to become a top defender in the near future.
Bas Dost is enjoying another profitable season at Sporting Lisbon. The 29-year-old has scored 20 goals in 28 games in all competitions and he has just shy of 100 goals in less than three seasons at Sporting CP.
The Netherlands international is an out-and-out goal scorer and he could be a veteran option for Pellegrini to consider.
West Ham wanted Joao Felix last summer (Sky Sports News) and they will be regretting this missed opportunity. The 19-year-old has broken into the Benfica first-team this season and caught the eye of numerous clubs.
With 11 goals and four assists in his debut season, the Portugal under-21 starlet has earned his first call up to the senior squad and is one of the best teenagers in world football.
Moussa Marega was another player West Ham wanted last summer (Sky Sports News). The Mali striker has scored 16 goals this season and could be a striker option for the Irons.
The 27-year-old Porto forward is renowned for his pace, power and ability to score goals, which is exactly what West Ham need.
West Ham could do with a top quality defensive midfielder to partner Declan Rice at The London stadium. Porto star Danilo Pereira fits the bill perfectly.
The 27-year-old has played nearly 150 games for Porto, 31 times for Portugal and is well-known for his powerful displays in central midfield.