Liverpool are in talks with Sporting Lisbon for several of their top prospects.
Reds chiefs were bowled over by the talent in Sporting's youth team during last season's NextGen Series.
Sport says goalkeeper Rafael Veloso and midfielder Joao Mario have both attracted a bid from Liverpool of €700,000 - which was rejected by Sporting.
Sporting teammate Tiago Ilori, whose agent is Pini Zahavi, is another interesting European clubs.