Manchester United and City are locked in a transfer battle to sign contract rebel Sanchez.
Arsenal boss Arsene Wenger is willing to do business before the transfer window closes but only if a club meets his £35million asking price.
And Balague believes that’s because a deal for a replacement is already done.
The Spanish football expert told Sky Sports’ Transfer Talk podcast: “If Alexis goes now they are prepared.
“They’ve got a name, they’ve got a player that will replace him.
“They don’t have to negotiate anything with him – it’s just a matter of seeing if Alexis leaves now or at the end of the season.
“They are prepared for the departure and they say he’s a big name and it’s not just a kid coming through.
“We’ll see what happens with that.
“At the moment, in terms of facts, Manchester United have not spoken to Arsenal. They have spoken to Alexis and the wages are higher than what City are offering Alexis.”
Express Sport understand Sanchez has been told to complete a move to Old Trafford this week – or forget about joining Manchester United.
Boss Jose Mourinho is keen on signing the Arsenal forward but United have set him a deadline of Friday to sign or they will withdraw their interest.
They fear that their pursuit of the striker is being used by Arsenal as a bargaining chip to get rivals Manchester City to increase their £20million offer.
While Arsenal want £35m, City believe that is too much for a player in the last six months of his contract who they could sign for nothing if they wait.
Sanchez will earn £13m a year and will be given a £30m signing-on fee by the League leaders if he joins in the summer.