Amidst the flurry of goals and excitement at Spurs’ 5-1 triumph over Bournemouth last weekend, a substitution made in the 68th minute went somewhat under the radar.

The change saw Mousa Dembele be replaced by Ryan Mason, who took the field for the first time since injuring himself in the 1-0 over Sunderland back in September, and presents Mauricio Pochettino with a selection dilemma heading into this Monday’s fixture against Aston Villa – does he reinstate Mason, or stick with the recently established Eric Dier / Dele Alli combination?

The improvement in results since Alli took Mason’s place in the team beside Dier (twelve points in five games as opposed to six points in five game) suggests the obvious decision would be to continue with the current pair. But it’s worth remembering that the injury that has kept him out the past month was came about in the process of scoring a crucial winning goal against Sunderland, that capped off an excellent performance that prompted tactics expert Michael Cox to call him ‘almost un-droppable’.

Does he reinstate Mason, or stick with the recently established Eric Dier / Dele Alli combination?

Whoever Pochettino chooses will be revealing of how happy he is so far with this season compared with last, as the contrast between the Dier / Alli partnership and the Mason/Nabil Bentaleb partnership that was the mainstay of 2014/15 has epitomised his new, more cautious campaign this season. Whereas the latter two’s attacking instincts and desire to win the ball high up in the opposition half led to attacking and open football, the more conservative approach of the former pair has drastically tightened up the defence, so much so that we currently enjoy the joint-best defensive record in the league.

This will have come as no surprise to the many who criticised Mason last season. He was singled out last season by many observers for his naivety and lack of both positional awareness and instinct to know the right time to press, and therefore blamed for much of our defensive woes. Bentaleb received a lot less flack, but was not perceived as defensively capable enough to cover the gaps left by Mason.

But such criticism was somewhat unfair. Although it’s true that their style of play as a pair was detrimental to the defence, what the critics failed to acknowledge was how much he contributes to the team’s attack. When Michael Cox called Mason ‘almost undroppable’ last month, he was referring to the 24-year-old’s quality distribution with the ball, his high energy levels, and his threatening forward runs off the ball.

Sure, Dier and Alli’s average tackles (both 3) and interceptions (2.8, 2.6) per game this season are both a lot higher than Mason’s (1.3 tackles and 0.5 interceptions), and sure, our defensive record as a whole is a lot better this season (8 goals conceded in 10 games) than last (53 goals conceded in 38 games).

But such defensive improvement has hardly propelled the team to another level – once again we’re just off the pace of the top four, averaging 1.7 points per game as opposed to last season’s 1.68. What has been gained in defensive solidity has been counterbalanced by a loss of offensive threat, as neither Alli nor Dier are as skilled in possession as Mason and Bentaleb.

The 4-1 win over Man City and 5-1 against Bournemouth were great attacking performances, but anomalies compared with the rest of the season – outside of those two thrashings we’ve managed just seven goals in nine games, scoring one goal or less in six.

In theory, Dier’s disciplined defensive positioning should provide Mason with the license to move forward without putting the back four in so much danger

The answer therefore could lie in striking a balance between last seasons’s attacking pair and this season’s defensive pair, and selecting Dier to play alongside Mason. Although the team got off to a lacklustre start to the season with that combination, the lack of goals in these games felt more like a problem with the front four than the midfield two, with Christian Eriksen out injured and Harry Kane off form.

In theory, Dier’s disciplined defensive positioning should provide Mason with the license to move forward without putting the back four in so much danger, and therefore run the midfield with possession and attacking thrust – just like he did playing alongside Dier against Sunderland.

Alli has shown great promise and looks set to be a future star, while Bentaleb should come under consideration again when he returns from injury. But for now, Mason and Dier look the best options to play in central midfield come Monday’s game at the Lane.