Jamie Redknapp has issued a warning to Ange Postecoglou after Tottenham's 1-0 defeat against Arsenal.
Spurs suffered their second consecutive Premier League loss this season and their third straight north London derby defeat at home on Sunday.
Gabriel's second half header proved to be the difference, with the Brazilian leaping highest from Bukayo Saka's inswinging corner.
The defeat has left Tottenham 13th in the table and Redknapp insists they need to start picking up results sooner rather than later.
The former midfielder said speaking on Sky Sports: 'This time last year Spurs were fantastic to watch.