Celtic are linked with a move for the 26-year-old hitman.
The Hoops already have two prolific goalscorers in the form of Odsonne Edouard and Leigh Griffiths, but Neil Lennon may want a third option.
In the same report, Cardiff City were also touted to be interested, but if they're the only two clubs left in the running then Celtic might have just gone ahead of them.
That is because according to Wales Online, City do not have any intention on signing the DR Congo international, who cost Boro a club-record £15 million in 2017.
The North-East English club want to recoup their £15 million investment and Team Talk have reported that Fulham and Sheffield United have already dropped their interest in Assombalonga, who has been a disappointment at the Riverside.
As of right now, it appears as if the Bhoys are the only club left standing in the race to sign him, but it's worth pointing out that they would have to smash their transfer record - which is £9 million - to get him.
It's a big decision by Lennon, but the good news is that he isn't under pressure to decide quickly because, well, it appears as if Celtic are the only club in the queue, if rumours are believed.
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