Joao Felix has reportedly informed Atletico Madrid that he wants to leave the club in January.
The 23-year-old has struggled to make his mark for Diego Simeone's side this season, only scoring three goals and registering three assists in 12 La Liga appearances.
Meanwhile, he failed to find the back of the net in five outings in the Champions League, with the capital giants finishing fourth in Group B to drop out of Europe altogether.
Felix still has four years left to run on his contract at Wanda Metropolitano, but there has been speculation surrounding his future over the last few months.
Manchester United have been heavily linked with the Portugal international, while there is also believed to be interest from Paris Saint-Germain and Bayern Munich.
According to The Mirror, Felix has told Atletico that he wants to leave the club during the January transfer window, and Man United are keeping a close eye on the situation.
The 20-time English champions are expected to be in the market for a new forward at the start of 2023 following Cristiano Ronaldo's exit from Old Trafford.
Ronaldo's contract was terminated following the explosive interview that he gave to Piers Morgan on TalkTV, and his departure has left Man United short of options in the final third of the field.
Man United were linked with the forward during his time at Benfica, but Atletico ultimately signed him in the summer of 2019, paying in the region of £113m for his signature.
Felix has scored 33 goals and registered 18 assists in 129 appearances for Atletico in all competitions, but his relationship with the club's head coach Simeone is believed to have become strained.
The forward has only started five La Liga matches this season, while he only featured in the starting XI on three occasions in their six games in the group stage of the Champions League.
Felix is currently with the Portugal squad at the 2022 World Cup, and he was on the scoresheet in their 3-2 success over Ghana on Thursday night.
Inter Milan's Lautaro Martinez, Barcelona's Memphis Depay, Napoli's Victor Osimhen and PSV Eindhoven's Cody Gakpo are also believed to be forward targets for Man United. body check tags ::
