The Bees hitman has hit the ground running this season in the Championship, with 25 goals to his name from 33 appearances.
Leeds could be in the market for a striker in the summer transfer window and Toney has already been linked with a host of Premier League sides.
However, former Leeds man Whelan believes Brentford will not sell Toney in the summer despite interest from top clubs, provided they earn promotion into the Premier League this season.
Whelan explained that Brentford had to sell their top players in previous terms as they failed to clinch promotion and will not be a selling club again if they can get over the line this time around; they currently sit fourth in the Championship.
“If Brentford get to the Premier League there is no way they are selling him [Toney]”, Whelan said on BBC Radio Leeds after the loss against West Ham, when Toney was floated as an option for the Whites.
“They will not be that team again.
“The reason they sell a lot of players is, once you do not get into the Premier League, they have got to offload.
“If they get to the Premier League, there is no way they will be letting him go.”
Brentford missed out on promotion last season after reaching the playoffs and cashed in on winger Said Benrahma, who made the move to West Ham.