Middlesbrough are demanding at least the £15 million which they paid Nottingham Forest in 2017 from any club who wishes to buy him this month.
Leeds United were credited with an interest in the proven Championship performer this week, according to The Mirror.
Assombalonga has missed the last nine league games through injury but is now battling back to full fitness.
Boro have picked up in recent weeks and the Northern Echo claims that Assombalonga won’t be going anywhere on the cheap.
The report cites that he is rated at £15 million and it seems highly unlikely that Leeds will consider paying such a sum.
Marcelo Bielsa is keen to add a striker to his ranks as he looks to replace Eddie Nketiah who recently returned to Arsenal.
Leeds have lost two on the spin in the Championship and are in danger of ruining their chances of promotion once again.
The failure to add players to the ranks at the halfway stage last season saw the Whites go on a disastrous run and lose out in the play-offs.
Middlesbrough clearly don’t want to sell one of their best players during this window and will demand a hefty price for Assombalonga.
Clubs will know that Leeds are desperate for a striker and there’s a danger that they might be held at ransom.
Paying £15 million for the 27-year-old wouldn’t be overly savvy on the business front and it could be back to the drawing board.
Leeds are being quoted silly money for lots of players and as the transfer deadline nears they might be forced into the European market.
It has worked for the Whites in the past and it club’s like Middlesbrough are going to hold out for top dollar, it could prove their best option.