Redknapp has criticised the quality of Tottenham's squad after they spent around £100m on seven new players in the summer of 2013 following Bale's move to Real Madrid.
"They want to get back in the top four but at the moment they could not be further from it," Redknapp wrote in the Daily Mail. "They have struggled ever since they sold Gareth Bale and most of the men they brought in have not been good enough.
"Spurs have spent plenty of money but how many of those transfers were for top-class players? Erik Lamela has not lived up to his billing and clearly Roberto Soldado is not the answer up front."