The Manchester United defender, as well as Jamaal Lascelles and Alex Pritchard, could make their first appearances for the Under-21s in the final two Euro 2015 qualifying fixtures
The versatile duo have both been handed chances to start games for their Premier League clubs due to injury, with Dier rewarding manager Mauricio Pochettino's faith by scoring two goals in his first two Spurs appearances.
Saido Berahino has earned another call-up after scoring seven goals in his first eight games for the Under-21s and netting two on the first weekend of the Premier League season for West Brom.
The likes of Harry Kane, also of Tottenham, and Danny Ings, of newly promoted Burnley, will aim to impress coach Gareth Southgate to win the chance to partner the Burundi-born forward.
Blackett, Newcastle defender Jamaal Lascelles, who has returned to Nottingham Forest on loan, and Brentford's on-loan Tottenham forward Alex Pritchard could all make their Under-21 debuts.
Those missing out on a place include Manchester United midfielders Wilfried Zaha and Nick Powell, Chelsea striker Patrick Bamford and Sunderland forward Connor Wickham.
The squad is made up of 16 players from Premier League clubs and five - goalkeeper Jonathan Bond, midfielders Jake Forster-Caskey and Will Hughes and forwards Nathan Redmond and Cauley Woodrow - from Championship sides.
The Under-21s have won seven and drawn one of their eight qualification games for the European Championship in 2015 and lead Moldova in Group 1 by six points and a significant goal difference advantage with two games remaining.
Squad in full:
Goalkeepers: Jonathan Bond (Watford), Jack Butland (Stoke City).
Defenders: Tyler Blackett (Manchester United), Eric Dier (Tottenham Hotspur), Luke Garbutt (Everton), Michael Keane (Manchester United), Jamaal Lascelles (Newcastle United, on loan to Nottingham Forest), Liam Moore (Leicester City), Jack Robinson (Liverpool).
Midfielders: Tom Carroll (Tottenham Hotspur, on loan to Swansea City), Nathaniel Chalobah (Chelsea), Jake Forster-Caskey (Brighton & Hove Albion), Will Hughes (Derby County), James Ward-Prowse (Southampton).
Forwards: Saido Berahino (West Bromwich Albion), Tom Ince (Hull City), Danny Ings (Burnley), Harry Kane (Tottenham Hotspur), Alex Pritchard (Tottenham Hotspur, on loan at Brentford), Nathan Redmond (Norwich City), Cauley Woodrow (Fulham).