Old Trafford No 2 Carlos Queiroz has been on scouting missions over the last few weeks to run the rule over Moutinho and Veloso, both former teammates of United stars Cristiano Ronaldo and Nani.
Moutinho, 21, has 11 caps for Portugal and his quick-footed, artistic style is perfectly suited to United. Veloso, also 21, is a more defensive midfielder who can also play as a centre-half or as a full-back. He has five Portugal caps to his name.
Queiroz watched the Sporting players in their Uefa Cup defeat to Rangers last week.
And it is believed that United have first refusal on the young stars but the champions-elect know they will need to shell out around £30m for the pair.
