Eric Dier
Villas-Boas has his eye on English-born Sporting starlet Dier. (Facebook)

Tottenham Hotspur will lodge a bid of £4.2m for Sporting Lisbon defender Eric Dier before the transfer window closes, reports in Portugal suggest.

Cheltenham-born Dier has progressed through Sporting's revered youth ranks since moving to Portugal from England as a ten-year-old and began to solidify himself as a regular member of the first team squad last season.

The centre half, who has also operated as a right back and a defensive midfielder, has often been linked with a return to England after the likes of Arsenal and Manchester United reportedly failed to convince him to leave Portugal before signing his first professional contract with Sporting in 2010.

But Portuguese newspaper Record suggests Andre Villas-Boas is very keen to bring the stylish defender to White Hart Lane this summer, and believes a bid of under £5m will be enough to convince Sporting to part with the Englishman.

The emphasis of Tottenham's transfer plans in recent weeks has largely been on possible attacking additions to the squad. With the future of Gareth Bale still uncertain, the likes of Roma forward Erik Lamela and Anzhi's Willian have been strongly linked with moves to the Premier League club.

But following the sale of Steven Caulker to Cardiff City earlier this month, Villas-Boas may possibly have his eye on another defensive recruit.

Dier, who made his debut for England Under 21's in a recent win over Scotland having already progressed through his country's younger ranks, has previously indicated he is happy to remain in Portugal, but still retains a dream of returning to England to win trophies.

"I am only 19, I am very young and Sporting is the right club for me right now," Dier told UEFA's official website earlier this month.

"I don't think about anything else. I want to win trophies and if one day I leave Sporting I want to do it with silverware. If I don't, I want to win titles here until the end of my career.

"That is my first goal, to win trophies. Then my objective is to play at the top level in England in the Premier League. That's my dream and ambition."