Liverpool have tabled a bid for Porto defender Bruno Martins Indi.
Fanatik says Liverpool have made a £4.3m opening bid for the 24-year-old.
However, Porto are said to want £6m while Liverpool could face competition from Turkish champions Besiktas.
Martins Indi has been capped 31 times by Holland and joined Porto in 2014 after impressive performances at the 2014 World Cup.