Tottenham's biggest players have gone missing and Ange Postecoglou has NO plan B

At the start of the season everything appeared to be on the right track for Tottenham, with the newly-appointed Ange Postecoglou guiding his side to eight victories in ten games as they enjoyed an unbeaten start to the Premier League campaign.

There was talk that Tottenham could win their first league title since 1961, but such discussions are now a distant memory, with Postecoglou's team currently in the midst of a miserable run of form as the season nears its conclusion.

Although it is still mathematically possible, securing Champions League qualification looks as if it will be a tall order for Tottenham, who have lost their last three games including defeats against rivals Arsenal and Chelsea.

The belief appears to have sapped away from Tottenham in recent games and Postecoglou will be eager to ensure that the problems don't run into next season.

Mail Sport assesses why Tottenham have struggled of late.

Struggles from set-pieces

Defending set-pieces has proven to be a major problem for Postecoglou's team, especially since December, and they have conceded 22 goals from such situations in the Premier League this season.

Postecoglou has claimed that he isn't especially bothered by the issue, saying: 'I'm not interested. Never have been. Not in the least.

'It's not the first time I've been questioned about set-pieces in my coaching career. There is an underlying reason for that which I'm very, very comfortable with.'

Tottenham were again vulnerable from set-pieces in their 2-0 defeat to Chelsea and there is little sign of the situation improving any time soon. Trevoh Chalobah put Chelsea in the lead with a header following a free-kick before Nicolas Jackson made it 2-0 as he found the net after Cole Palmer's free-kick had hit the crossbar.

With teams now fully aware that this is an area of vulnerability for Tottenham, they will look to exploit it as much as possible.

Too often, the positioning of players at set-pieces hasn't been effective and has provided the opposition with space to run into. It is an alarming state of affairs that needs addressing but it doesn't look as if things will change any time soon.

Lack of quality depth

There are undoubtedly some talented players in the Tottenham team, but there are also question marks over the depth in the squad.

Although Son Heung-min has contributed with 16 Premier League goals and Richarlison has scored ten, no other Tottenham players have reached double figures this season, and the feeling persists that one of the reasons Spurs are struggling is their failure to replace Harry Kane.

Kane has continued to score with regularity in the Bundesliga this season, getting 35 goals for Bayern Munich, and his presence would undoubtedly have significantly improved this Tottenham team.

Some of Tottenham's options from the bench are unconvincing. Against Chelsea, for instance, Bryan Gil featured as a substitute, but the winger appears to have no long-term future at the club.

The injury to Destiny Udogie, who produced some excellent performances earlier in the campaign, has hit Tottenham hard, especially with Ben Davies, the club's other main left-back option, also sidelined.

No plan-B from Postecoglou

When Tottenham were swatting aside teams with Postecoglou's attacking style of play there was no need for the manager to consider altering his approach.

Now, though, Postecoglou remains committed to his style of play even though it is no longer being backed up by results.

Despite the difficulties that Tottenham are enduring and how vulnerable their defence has been at times, Postecoglou has remained steadfast in his belief that he won't alter his principles.

Some adaptability is needed, however, as clubs are now familiar with Tottenham's style of play and know how to exploit their weaknesses.

Spurs are way too open at times and there has also been a lack of cohesion.

Postecoglou needs to ensure that his team has greater flexibility by reigning in their attacking instincts when necessary.

Form of big players has dropped off

At this stage of the season you need your star players to stand up and be counted, but in many instances that hasn't been the case for Tottenham.

James Maddison, for instance, showed some encouraging signs after joining Tottenham from Leicester, but he hasn't scored or assisted in his last seven league games.

Maddison only featured as a substitute against Chelsea after struggling against Arsenal, and appears to be lacking his usual conviction with regards to his passing.

Dejan Kulusevski, meanwhile, was subdued against Chelsea and hasn't scored in his last nine league appearances.

Postecoglou has needed some of his big players to step up but that often hasn't proven to be the case at crucial moments.

Lack of leadership and experience

Another issue for Tottenham is the lack of experience in the squad.

Son and Davies are the only outfield players who are over the age of 30, while aside from Son some of the standout stars have been the likes of 21-year-old Udogie and 23-year-old Micky van de Ven.

Bringing a bit more experience into the team during the summer transfer window could be a significant step forwards for Tottenham.

The lack of leadership in the squad is also a cause for concern, with Tottenham not having many players that are capable of dragging the team out of difficult situations.

Some of the players in the squad could well develop into leaders, but more experience is required.