Tottenham manager Thomas Frank has played down criticism after being pictured drinking from an Arsenal-branded cup during his side’s 3-2 defeat to Bournemouth, a result that intensified pressure on his position.

The image, taken on the touchline at the Vitality Stadium, provoked anger among Spurs supporters given Arsenal’s status as their fiercest rivals.

Frank insisted the incident was accidental and unrelated to his team’s performance. “I definitely didn’t notice it,” he said. “I think it’s fair to say we’re not winning every single football match so it would be absolutely, completely stupid of me to take a cup from Arsenal.

They have been in the changing room the game before us. It’s normal to take a cup, give me an espresso, I do that before every game, so I think actually it’s a little bit sad in football that I need to be asked a question about that. We’re definitely going in the wrong direction if we need to be worried about me having a cup with a logo of another club. Of course I would never do that. That’s extremely stupid.”

On the pitch, Tottenham’s poor run continued. Mathys Tel gave them an early lead, but Bournemouth responded with goals from Evanilson and Eli Junior Kroupi. Joao Palhinha’s bicycle kick appeared to rescue a point before Antoine Semenyo struck in stoppage time to secure victory for the hosts.

The defeat left Spurs with only two wins from their last 12 league matches and sparked heated exchanges between fans and players at full-time.

Frank admitted the result was difficult to accept. “I think it’s fair to say everyone involved in Tottenham, it’s a tough one to take today. Hopefully everyone can see how hard we worked to get everything in the right direction.

Overall the performance was good, especially the second half, in a game where we deserved to get more. That is extremely painful to be part of, so of course people are frustrated, that’s natural.”

Semenyo, celebrating his 26th birthday, was given a standing ovation when substituted after scoring his tenth goal of the season.

Bournemouth manager Andoni Iraola praised his forward, saying, “He deserved this moment; I’m happy football has given him this moment he will not forget. It’s not easy to do what he has done because a lot of the players would have acted differently. He’s never found excuses.”

The defeat has left Frank facing mounting scrutiny just eight months after arriving from Brentford, with Tottenham’s season continuing to falter both on and off the pitch.