Arsene Wenger is looking for options to strengthen his backline, particularly if club captain Thomas Vermaelen leaves the Emirates this summer.
And England Under-21 defender Dier is said to be on his radar after breaking into the Sporting first-team in the last two seasons.
Dier moved to Lisbon aged 10 when his mother was offered work during Euro 2004, and has lived there ever since.
But it has been suggested he is ready for a move back to England – and O Jogo claim Sporting are willing to sell for just €6m, which is less than £5m.
And that figure could tempt Wenger to make an offer for the highly-rated youngster.
Written by Steve Milne
