"When the stress and fatigue arrived, that is our reality," Pochettino said, explaining his team's below-par display. "We are a very competitive team when we are with full energy. We are so focused.
"The stress and the fatigue arrived, and we are competing with circumstances that are not the best."
With injuries limiting his ability to rotate the team amid a gruelling schedule of games every three or four days, Pochettino played a close-to-full-strength team against West Ham.
Ideally, he would have rested key players such as Christian Eriksen and Dele Alli.
Fortress Tottenham was breached for the first time by a visiting team since the state-of-the-art stadium finally opened almost a month ago. Michail Antonio chested down Marko Arnautovic's superbly-placed cross and volleyed into the far corner to secure victory.
Spurs finished the game with Fernando Llorente and Vincent Janssen, two long-overlooked and often-maligned strikers, as their forward line.
As it is, Tottenham host Ajax in the first leg on Wednesday with Harry Kane, Harry Winks and Erik Lamela among those injured, Heung-min Son suspended and doubt over the fitness of increasingly influential midfielder Moussa Sissoko.
To make things worse for Spurs, Ajax's players had their feet up this weekend. All fixtures in the Dutch top flight were cancelled in an effort to help Ajax stay fresh for the semifinal. The Amsterdam club will go into the first leg on the back of a week's rest.
Behind the fraught four-team battle for Champions League qualification, Wolverhampton Wanderers look on course to finish seventh and potentially earn a spot in the Europa League next season.
Wolves won 2-1 at Watford to consolidate seventh. With Everton drawing 0-0 at Crystal Palace, Wolves are four points clear of Watford and Everton with two games left.
Diogo Jota led Wolves to victory, setting up Raul Jimenez for the opener in the 41st minute and volleying the winner in the 77th after Watford keeper Ben Foster misjudged a deep cross.
In the relegation battle, Cardiff look to be heading back to the Championship after just one season. The Welsh club lost 1-0 at already-relegated Fulham and then saw relegation rivals Brighton draw with Newcastle 1-1 in the late game. Cardiff are third-to-last, four points behind Brighton with two games left. Brighton have a superior goal difference of 14.
Cardiff's final two matches are against Palace and Manchester United, while Brighton still have to play Arsenal and Manchester City.
Cardiff's loss guaranteed the survival of Southampton, who drew a wild game against southern rivals Bournemouth 3-3.
- AP
