Modric has been strongly linked with a move to Manchester United and Corluka fears the playmaker could leave in order to get Champions League football.
“We all know it will be very difficult for Spurs to keep Luka because they do not have Champions League football next season,” Corluka is quoted as saying in The Sun.
“Luka is one of the best players in the world and the kind who wants to play in the best competition.
“Not getting into the Champions League will cost Spurs next season, even though they were unlucky to get fourth place and still not be there.”
