Manchester United have shown "concrete interest" in signing Atletico Madrid forward Antoine Griezmann, who has an exit clause of £85 million ($108.79 million), the Frenchman's agent Eric Olhats has said.

United, who are fifth in the Premier League, have scored the least number of goals among the top six sides and are aiming to strengthen their attack with Griezmann, who has scored 25 goals for Atletico this season.

"We're at the stage of gathering information from clubs who have a concrete interest," Olhats told French television programme Téléfoot.

"There is an unavoidable €100 million (about £85 million) clause so that restricts the number of candidates. You have United, (Manchester) City, Chelsea, Barcelona and Real Madrid.

"United were the first to come and see us and the most concrete in their wishes."

United's attacking options are limited with top goalscorer Zlatan Ibrahimovic ruled out for the season after sustaining a serious knee injury in their Europa League tie against Anderlecht.

Injured midfielder Juan Mata is the next highest scorer this season for the club with six strikes while 19-year-old striker Marcus Rashford has five.

United travel to face local rivals Manchester City on Thursday as both teams aim to secure a top four finish for a Champions League berth.