Manchester United boss Sir Alex Ferguson had scouts in the stands for Sporting Lisbon's 2-2 draw with Roma.
Sporting midfielder Miguel Veloso is a top target for United ahead of the January market, while young attacking midfielder Yannick Djalo is another identified by United assistant manager Carlos Queiroz this season.
Interestingly, Arsenal, which are also being linked with Veloso, were not among the seven Premiership clubs represented at Sporting last night.