Bale and Modric have been close dating back to their days in the Premier League with Tottenham.
Real Madrid are on the lookout for summer reinforcements – with Paris Saint-Germain's Marco Verratti and Liverpool's Philippe Coutinho on their radar.
However, Spanish outlet Don Balon claims Bale is against Real shelling out on another central midfielder.
Gareth Bale feels Luka Modric still has plenty to offer to Real Madrid Real Madrid wages revealed: Which stars earn most? Fri, March 24, 2017
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Click to reveal every Real Madrid player's weekly wages
Bale believes Modric remains a key asset to the club, despite his form waning in recent weeks.
The Wales international wants his team-mate to stay and fears the arrival of another player in his position could force him towards the exit door.
Bernardo Silva and Marco Verratti have both been linked with moves to Real Madrid
Bale also feels Monaco ace Bernardo Silva is not needed at the Bernabeu.
Silva has been a huge hit in Ligue 1 and, should Real heed Bale's advice, Manchester United and Barcelona could try to sign the Portugal international.
As well as the PSG, Liverpool and Monaco stars, reports have previously claimed the Madrid star is also against the club signing Eden Hazard from Chelsea.
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