Manchester City's Ruben Dias is the current favourite, partly because of the club's potential treble of the Champions League, Premier League and Carabao Cup. But Mason argues that Kane is the most significant player of the season, regardless of Tottenham's form.
"I wasn't aware Harry wouldn't be in that conversation because, in previous seasons, players have won without winning the league," said Mason.
"Harry has been the most influential player in the Premier League this season. He's got the joint-most goals, most assists. If the prize is who is the best player in the Premier League, then Harry has to be in the conversation.
"Consistently over the last five or six years, Harry has been one of the best players in the Premier League and this year has been no different for him.
"The trophy isn't for the team of the league, it's for the player of the league. He's one of the best players in the world, and statistically this season he has probably produced the best numbers. So why is he not in that conversation?"