The two Englishman were excellent in Spurs' victory over Sunderland earlier today.
The importance of the holding two in a 4-2-3-1 formation cannot be understated and finding the right balance is no easy task.
The wrong combination can leave a team lacking in creativity or over-exposed at the back and Tottenham’s turnover of countless central midfielders in recent years highlights the difficulty in finding a complementary pair.
The former Sporting Lisbon man had been trialled as a holding midfielder in pre-season and made his bow to great effect against Manchester United.
Bentaleb, on the other hand, was poor and found himself out of the team as Mason returned to full fitness.
Aside from Eriksen’s absence forcing Pochettino to play Mason further forward against Everton, the England international has been partnered with his England Under-21 colleague three times this season – and it appears to be working.
Both were excellent in today’s 1-0 win over Sunderland and have now established themselves as first-choice beyond any doubt.
Dier is quickly earning a reputation for his robust tackles and made the most on the pitch today (8) in what proved to be a man of the match performance.
Mason’s natural attacking instincts (he was a no. 10 in his younger years) complement his midfield partner perfectly, and his willingness to break forward is something Spurs have desperately been lacking in recent years.
His sublime goal typifies what he can provide for Spurs from deeper areas and it’s the security of Dier that allows him to do it.
The former Sporting Lisbon youngster almost operates as a third central defender at times and allows those ahead the freedom to express themselves.
Today’s victory was Spurs’ second clean-sheet in a row and their new approach seems to be paying dividends, with Pochettino’s men boasting the joint fourth best defensive record in the Premier League after five games.
Both have room for improvement - with Dier needing to work on his distribution and Mason needing to maintain a consistent goal threat - but the signs are promising, and after 16 months of searching - Pochettino may finally have found his midfield solution.