Liverpool scouts were in the stands to see Sporting CP in action at Vitoria Setubal.
Record says Reds scouts were joined by representatives from Valencia, Southampton, Stoke City and QPR.
Carlos Mane and Junya Tanaka struck for Sporting in the 2-1 win.
On show for the Lisbon giants were Nani, Mane and William Carvalho. Sporting goalkeeper Rui Patricio, who has been linked with Liverpool, also featured.