LONDON -- Tottenham Hotspur captain Son Heung-min said the players needed to look in the mirror after a damaging 3-0 loss at Fulham cast doubt on their Premier League top four credentials on Saturday.

Victory would have put them ahead of Aston Villa into the guaranteed Champions League berths but they produced a limp display as Rodrigo Muniz scored twice for the hosts.

"It is very disappointing and very frustrating. Everybody has to look in the mirror and say 'it is my fault'," said Son, who wasted one chance when the score was 0-0.

"It was not good enough. We didn't put in the effort we have put in this season. The performance, the attitude was not good enough. Everyone needs a big wake-up call."

The performance was all the more surprising given Tottenham's clinical 4-0 win at Villa last weekend and it ended their run of scoring in every Premier League game this season.

Son was certainly not mincing his words.

"In the Premier League if you are not ready you get punished. Aston Villa are an amazing team, but so are Fulham. If you are not giving 100% you get punished. You don't get three points for free," the South Korea forward added.

"This is two steps backwards. We now need to step forward. It is unacceptable, including me it was unacceptable.

"We are representing Premier League teams, we are representing Tottenham. This was not close to what we have been doing this season. It is very sad to watch this. The fans don't deserve this. Losing this was very tough."