Johnson has emerged as Spurs’ next transfer target of another busy summer which has seen them spend around £165million, but also recoup more than £100m with the sale of Harry Kane to Bayern Munich.
Spurs have decided rather than signing an outright replacement for Kane they will spread the goals across the squad, and the imminent push to sign the 22-year-old, who can play across the forward line, is part of that strategy.
Forest do not want to lose a player who scored 10 goals, and added three assists, last season and will demand £50million for Johnson, who is homegrown.
Spurs are unwilling to pay that much for Johnson and will attempt to negotiate a lower fee.
Forest earlier in the window rejected a bid worth close to £40m from Brentford for the Wales international, who is also of interest to Chelsea.
Spurs are also keen on reducing the size of their squad before Friday’s 11pm deadline. The likes of Davinson Sanchez, Eric Dier, Tanguy Ndombele, Djed Spence and Hugo Lloris could all leave.
Asked on earlier this week if Spurs must sell before they buy again, manager Ange Postecoglou said: “Not necessarily. These kind of things are pretty fluid, they can happen pretty quickly.
“At the moment you can see by doing the maths we have got too many players in terms of when we submit our final list, there will be guys here who won't be on that list if nothing changes so I am pretty sure that will change. From now until the end of the window I am sure there will be some movement.”