After overcoming so many hurdles, Mauricio Pochettino faces his biggest challenge yet at Tottenham: fatigue

The evidence of Tottenham's victory over Chelsea is that they are running on empty. There is almost nothing left in the tank

Tottenham Hotspur at their best are above all a physical force, a wave of white shirts sweeping across the pitch, crashing over the opposition, a synchronised stampede of players which no obstacle can stop.

At times in recent weeks that is just what Spurs have looked like. When they won 6-2 at Goodison Park just before Christmas, or when they put five past Bournemouth here at Wembley on Boxing Day. Or even back in November when they beat Chelsea 3-1 but should have scored twice as many as that.

Mauricio Pochettino is performing better than ever right now, driving his thin squad on to consistent performances that many thought beyond them this year. But while he can push the boundaries of physical exertion, he cannot conquer them. This Spurs teams is still made up of human beings, with physical bodies, who can only do so much for so long.

Because the evidence of Tuesday night is that this Tottenham team is running on empty. They have given so much in the last few weeks that it has drained their energy. There is almost nothing left in the tank.

So often with Spurs we are used to them finding an extra physical level when their opponent starts to flag. Here we were presented with an unfamiliar picture, as Tottenham tired in front of our eyes in the second half. While they were dangerous from the start, and probably deserved their lead, they offered almost nothing going forward after the goal. The longer this game went on the better Chelsea got, like their 2-0 defeat of Manchester City one month ago. They just never scored the goal their dominance deserved.

It was unusual to see a Spurs side retreat like this, but then this team has been performing in unusual conditions. Playing out from the back is meant to be their strength but they spent much of the second half just giving the ball back to Chelsea. Toby Alderweireld’s distribution is usually a strength, and it was his pass to Harry Kane that won the early penalty. But by the end here he was hacking the ball away to no-one, firing it over the heads of his full-backs, nothing ever able to stick.

At their best Tottenham seize control of midfield and never let up, but they were desperately second best in midfield here tonight. Harry Winks and Moussa Sissoko might not have been first choice at the start of the season but they have been indispensable in recent weeks, forced to play almost every game together. Winks started the season shaking off ankle pain but has now started nine of Spurs’ last 11 games, missing only the wins over Burnley and Tranmere. Sissoko was on the transfer list in the summer but has now started 13 of Spurs’ last 15 games, adding a muscularity and drive in the middle that no-one else can give them.

The fact that Winks and Sissoko have been the twin pistons for this special Spurs run only makes it more impressive. They have each found a new level within themselves, playing more consistently than they have done for Spurs before. But it was never going to last forever. And last night Winks and Sissoko’s workload seemed to catch up with them.

For long spells of the second half Sissoko and Winks could barely lay a finger on the Chelsea midfield, who were able to pass and move around them at will. Winks was inhibited by an early booking for a foul on Eden Hazard and that limited what he could do. Sissoko looked dangerous at times running forward but his most memorable moment came when he hacked a blind crossfield pass out to the left, ending a Spurs move and starting one for the opposition.

Mauricio Pochettino's side will have to cope with fatigue in the coming weeks (Getty)

Pochettino brought on Oliver Skipp at the end, and he is talented but he is also 18 years old. But with Eric Dier still not back in training after appendicitis, and Mousa Dembele on his way to China, Spurs are still obviously short in midfield. They would like to find a solution in the transfer market but that is never easy for anyone at this time of year, never mind for a team with hundreds of millions of pounds of stadium debt to their name.

Manchester United come here on Sunday and while Spurs should beat them, they must know that they will need more energy in midfield to put them on the back foot. To say nothing of the return leg for this fixture back at Stamford Bridge. They have done well to get this far, but to keep competing, with their midfield running on fumes, would be their biggest challenge of the year yet.