Ronald Koeman has made Saints’ defence a force to be reckoned with this season – but needs to work his magic on a stuttering attack to ensure his side keep moving in the right direction.

Defeat to Liverpool last Sunday meant Saints dropped out of the top four for the first time in 2015 as the race for Champions League football took another twist.

With Chelsea and Manchester City battling it out for the Premier League title, five must fit into two as Arsenal, Manchester United, Saints, Liverpool and Tottenham look to join them in Europe's elite competition next season.

That Saints are capable of hanging with the Premier League heavyweights this season is largely down to a drastically improved defensive durability.

Last season under Mauricio Pochettino, Saints’ opponents were restricted to just 9.6 shots per match - the second fewest in the division. This term they have tightened up even further, allowing a Premier League low of just 9.2 efforts at their goal per game.

The stark difference between Pochettino’s defence and Koeman’s, however, is how many shots it takes their opponents to score.

Last season, despite the presence of Dejan Lovren and Luke Shaw, they were breached easily – in fact only relegated Fulham were less resilient – but this time around there has been a full swing.

Only West Ham have soaked up more efforts than the average of 12.6 it typically takes opponents to find the back of Fraser Forster’s net.

These numbers, along with the fact they have conceded the fewest goals in the division (19), makes their defence the envy of their rivals.

Pochettino’s Tottenham have conceded nearly twice as many, while the 12 clean sheets Saints have kept is two more than Liverpool have managed, four more than Arsenal and only one fewer than Spurs and Manchester United combined.

Koeman’s challenge for the remainder of this season – and arguably over the summer – will be orchestrating similar progress in attack, a task he has yet to complete.

It's not that Saints’ attack has regressed – at their current scoring rate they are on course to finish with marginally more goals than last season (56 v 54) – they just haven't improved as dramatically as their defence.

While their 38 goals this season is the joint-fewest of teams chasing a top four place, along with Liverpool, Saints' haul would look much more disappointing without their 8-0 hammering of Sunderland earlier in the season.

Take away the 8-0 win, and Saints’ average goals per game in their other 25 league matches is just 1.2.

Over the course of a 38-game league season, that would equate to 46 goals – eight less than they scored under Pochettino last term.

Digging further into the numbers reveals more cause for concern.

Saints have failed to score in eight games this season – more often than any of their rivals – and on only nine occasions have they netted more than once.

That is despite having managed more efforts at goal than Manchester United this season, and more on-target efforts than Louis Van Gaal’s men as well.

In contrast to Saints, though, Arsenal have scored more than once in 17 games with only two blanks drawn.

Given last summer’s upheaval, it is remarkable that Saints are challenging the top four in the first instance.

But, as Liverpool found out last season, being proficient at one end and not the other will ultimately limit the opportunities for success.