Ligue 1 champions PSG and Premier League side Manchester United are reportedly in a tug-of-war for the services of Di Maria after Real Madrid boss Carlo Ancelotti revealed on Thursday the star winger had asked to leave the UEFA Champions League winners.
The French capital club's attempts to sign Di Maria have proved difficult thus far due to financial implications for breaching FFP rules last season.
PSG have already spent €58 million on defensive pair David Luiz and Serge Aurier, meaning Blanc must part ways with one of his prized assets before he can make a move for the 26-year-old Argentina international.
"There are many clubs interested in Di Maria. PSG cannot do what we want. It's a difficult case," Blanc told reporters ahead of Saturday's trip to Evian.
"PSG cannot do what it wants in terms of recruitment [because of financial fair play]. This is a difficult issue, the president has confirmed to me."
While prising Di Maria away from the Bernabeu appears to be an uphill battle, it did not stop fellow Argentina international Javier Pastore from talking up a potential transfer.
"He's a great player. If he joins that's good for PSG. He did very well last year at Real and also with Argentina in the World Cup," said Pastore.
"If he comes it will be to keep on winning silverware."
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