Jorge Mendes was an interested spectator as he watched Manchester United's clash with Wolves on Wednesday night.
The two Premier League sides faced off at Old Trafford in the FA Cup third round replay.
Super-agent Mendes has been involved in a number of deals to take players to Wolves in the past, and works as an adviser to the club, but his presence alerted Manchester United fans.
Mendes has been drafted in to accelerate a deal between the Red Devils and Sporting Lisbon midfielder Bruno Fernandes.
The agent has been in London over the last few days having worked on a deal to take Gedson Fernandes to Tottenham .
Mendes is not Fernandes' permanent agent but he has a strong working relationship with United.
He has now got involved in the deal and was in the directors' box at Old Trafford for the clash with Wolves.
The Red Devils are moving to secure the transfer of midfielder Fernandes having already agreed a fee in principle of £50million rising to £65m.
But according to Portuguese publication O Jogo, Sporting are slowing down the process in a bid to 'play for time,' having originally appeared set to sell this week.
The reason is apparently down to Sporting's next fixture.
They face their biggest rivals Benfica on Friday night, which is their most important match in the Primeira Liga season.
It is now unclear how long it would take for Fernandes to become a United player - although it is expected to still be completed before the end of the month.
