William Gallas believes that his former club Tottenham Hotspur need to recruit "top-class" defenders if they wish to qualify for the Champions League and compete for trophies.
After keeping three clean sheet in their opening three Premier League games, Spurs have since conceded 10 goals in their last four matches across all competitions, including two 3-0 defeats against London rivals Crystal Palace and Chelsea.
Nuno Espirito Santo signed two defenders over the summer, recruiting centre-back Cristian Romero and right-back Emerson Royal for close to £80m combined, however Gallas still believes the Lilywhites lack quality at the back.
"To improve their defence, they have to bring in top-class players. At the moment they don't have top class defenders," the former Chelsea and Arsenal centre-back told Genting Casino.
"If Spurs want to qualify for the Champions League and compete for titles they need to bring the right players at the back. At the moment they don't have the right players.
"I think it will be a really difficult season for Tottenham. They need top-class defenders and they didn't sign any top-class defenders."
Tottenham are now preparing for the North London derby against Arsenal at the Emirates Stadium on Sunday, with both Romero and Emerson in contention to start.