Anthony Elanga is set to become Newcastle's first major signing of the transfer window after the Magpies reportedly agreed a £55 million ($75 million) deal with Nottingham Forest.
The Athletic, BBC and Sky Sports all reported on Tuesday that the Swedish international is on his way to St James' Park.
Elanga was one of the stars of Forest's surprise seventh-placed finish in the Premier League last season, scoring six goals and providing 11 assists.
Forest paid just £15m to sign Elanga from Manchester United two years ago.
Newcastle's attempts to strengthen their squad in preparation for a return to the Champions League next season have so far been frustrated.
Despite being backed by the Saudi sovereign wealth fund, the League Cup winners have been limited in what they can spend in recent seasons by financial sustainability rules.