Felix has a huge release clause, but interested clubs will try to get him for less, according to Goal.
The 17-year-old is regarded as one of world football's biggest talents and has 16 goals and nine assists in all competitions so far this season.
He scored a Europa League hat-trick last week against Eintracht Frankfurt – making him the youngest player to do so in competition history – and Manchester City's sporting director Txiki Begiristain was reportedly present at the game.
However, City are reportedly reluctant to enter a bidding war with United and Juventus for Felix, and are seeking other routes to get a deal done.
One such avenue is thought to be through super-agent Jorge Mendes.
Mendes has clients on City's books already and has previously leveraged big purchases with sales of others within the club.
Juventus also believe they could use Mendes to help them get a deal, given his biggest client and Felix's compatriot Cristiano Ronaldo plays for the Old Lady.
All clubs involved, however, are reluctant to pay the full release clause – which Benfica are adamant is the price for now.
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