Antonio Conte’s side dropped points in the hunt for a top four finish on Saturday when they were held to a 3-3 draw away at Southampton.
Tottenham were 1-0 up at the break and even though Southampton levelled shortly into the second half, then scored twice to hold a comfortable 3-1 advantage with just 16 minutes left.
Two late goals for the hosts though, the second an injury time penalty, were enough to see the spoils shared and Tottenham’s top four hopes damaged.
Roberts was left alarmed by the quality of Tottenham’s defending at times and urged the club to bring in new defenders in the summer window.
“We need some new defenders next season urgently”, Roberts wrote on Twitter.
“Not good enough.”
The result sees Tottenham stay in fourth place in the Premier League table, two points ahead of Newcastle United, but having played two more games than the Magpies.
Liverpool sit sixth, seven points worse off than Spurs, but also have two games in hand on Conte’s men.
