The Gunners have struggled under Arsene Wenger and look likely to miss out on the top four for the first time under his stewardship.
Spurs are challenging Chelsea for the title, sitting four points behind the leaders, and Keown concedes there has been a big change between them and his old side.
Tottenham v Arsenal: Combined XI Fri, April 28, 2017
Express Sport brings you our combined XI of Arsenal and Tottenham stars ahead of the North London derby
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Express Sport brings you our Tottenham and Arsenal combined XI
Arsenal legend Martin Keown admits he is jealous of Tottenham
hey know they've got a special team there. They're better than Arsenal. It comes from a core of British players
Arsenal legend Martin Keown on Tottenham
"A few years ago Tottenham were a good 10-15 years behind Arsenal in terms of club development, the training ground," he said on BT Sport.
"They are striving for excellence at Tottenham. Their training ground is quite magnificent. Their ground is evolving into something really special.
"They are striving to develop and compete with the best teams. If you go to White Hart Lane, we used to call it Three Point Lane, the fans are in harmony with the team.
Martin Keown says Tottenham are a better team than Arsenal
"They know they've got a special team there. They're better than Arsenal. It comes from a core of British players.
"You have to look with envy. They've got winners in that group, they take responsibility. Who's best?
"Is it Kane? Is it Dele Alli? You've also got the Belgian players in there, brilliant players."