The Belgian midfielder bolsters Steve Cooper’s squad, with Ryan Yates, Jack Colback and Lewis O’Brien the only other players vying for the central midfield partnership.
The 24-year-old had been at Stuttgart since 2017 and has represented Belgium at every level from U15 through to two full international caps earlier this year.
Adam Khan, a German football writer, describes him as ‘a powerful midfielder with natural strength and speed, Mangala is capable of driving through opposition midfields, gaining valuable yards up the pitch’.
And Nick Miller, writing in The Athletic, says: ‘Mangala should prove to be a box-to-box midfielder with qualities that are otherwise absent from the Forest team, and he is capable of performing a couple of different roles in Cooper’s side. There is a sense that when surrounded by better players than he was at Stuttgart, he could flourish. If used the right way, he could prove to be a significant asset.’
Burnley’s Maxwel Cornet continues to be discussed as a target, although his release clause is believed to be £17.5m. Real Betis’s left-back Alex Moreno has also been linked, while another attacking midfielder and a central midfielder will surely arrive before the transfer window closes in a month.
Forest kick off the season next Saturday against Newcastle United at St. James’ Park, with the first XI likely to feature seven new signings.