The ex-Arsenal midfielder believes Spurs could not do without the 21-year-old, whom he praised the club for tying down to a new long-term contract.
The Gunners, however, could live without their star man Alexis Sanchez, the 46-year-old claims.
"Arsenal will miss Alexis Sanchez because he's top drawer but they got by without him last week. I don't think Tottenham could do without Harry Kane but Arsenal could live without Sanchez," Merson said.
"Signing Kane up was a huge deal for Tottenham - one of the best of the window."
In the short term, Merson's claims make sense - Arsenal won 5-0 without Sanchez against Aston Villa, while Kane has been a frequent scorer for Tottenham in recent weeks.
Over the course of the season, however, Sanchez has accounted for 44 per cent of the Gunners' league goals (in terms of both scoring and assisting).
|Goals (per game)||Assists||Appearances||Minutes Played|
As Opta stats show, Arsenal have scored more goals than Spurs, while Olivier Giroud averages more per game than Sanchez - giving credence to Merson's suggestions.
But Sanchez has averaged more goals per game than Kane (granted, the 21-year-old has played less minutes) and plenty more assists.
Tottenham's Christian Eriksen and Nacer Chadli, meanwhile, have been far more active in front of goal than any other Arsenal player - of which Santi Cazorla is the best example outside of Sanchez and Giroud.