Tottenham lost ground in the race to secure a top-four finish in the Premier League as they were held to a damaging 0-0 draw at Brentford on Saturday.
Antonio Conte's side dropped down to fifth place after failing to muster a single shot on target for a second successive game.
Arsenal's 3-1 win against Manchester United earlier on Saturday had lifted them above Tottenham into fourth place and thrown down the gauntlet to their north London rivals in the race to qualify for next season's Champions League.
Tottenham's response to that challenge was far from impressive and Arsenal now sit two points above them with five matches left.
Conte will be concerned that Tottenham's goals have dried up at the worst possible time.
"Defensively we were good but at the same time I think we can do much better with the ball to create chances to score," he said.
Having thrashed both Newcastle and Aston Villa at the start of April, Tottenham have drawn a blank for the last two matches.
With a potentially decisive showdown against Arsenal looming on May 12, Conte's men must rediscover their goalscoring touch quickly.
"We are trying to do our best. We started in a low position in November and I think we made many improvements," Conte said.
"We have to continue to improve because I think it is not enough if we want to stay in this race."
Brentford threatened early on as Bryan Mbuemo's shot deflected just wide before Ivan Toney had a volley blocked.
Christian Eriksen was given a standing ovation by Tottenham's fans in one corner of the Community Shield as he played against his former club for the first time since his cardiac arrest at the European Championship last year.
Brentford had won all five games the Denmark midfielder had started since his January arrival and Eriksen nearly set up an opener when his corner reached Toney, whose header thumped off the crossbar.
The same duo combined to open up the Tottenham defence again midway through the first half, with Toney's volley from Eriksen's cross deflecting just wide.
Tottenham were struggling to find their rhythm, a malaise encapsulated by the sight of Son Heung-min trying a cross that rolled harmlessly out of play.
Harry Kane turned Pontus Jansson sharply in the Brentford area soon after the interval, but the defender managed a block that sent his shot spinning over.
Tottenham remained fragile and Eriksen flashed a fierce drive just wide from the edge of the area.
Kane alertly headed Jansson's effort off the line before Lloris saved Eriksen's strike from the rebound.
With no sign of Tottenham's forwards sparking into life, it was Brentford who finished stronger.
Toney almost won it in stoppage-time when his header from Eriksen's free-kick cannoned off the post.
Kane went close in the last seconds, but his overhead kick from Dejan Kulusevski's cross was inches wide.