Assombalonga has been on the books of Middlesbrough since the summer of 2017 when he joined from Forest for a transfer fee reported by BBC Sport to be worth £15 million.
The 25-year-old striker played well for Boro last season, as the former Watford man scored 15 goals in 34 Championship starts, and, according to The Northern Echo, Tony Pulis’s side will not sell him on the cheap this summer.
Good signing for Nottingham Forest or Birmingham City?
Assombalonga is a very good striker who has proved himself in the Championship, and the 25-year-old would be a good signing for Forest or City, both of whom will be aiming for promotion from the Championship next season.
The DR Congo international was on the books of Forest from 2014 until 2017 and was quite successful during his spell at the City Ground, although he did have a serious knee injury.