Barcelona are watching Willem II sensation Alexander Isak.

The Swedish youngster has been outstanding for Willem since arriving in January on-loan from Borussia Dortmund.

Isak turned down an offer from Real Madrid two years ago, but could yet move to Barca this summer thanks to his superb form in Holland.

Mundo Deportivo says Barca see Isak as an alternative to Eintracht Frankfurt striker Luka Jovic, on-loan from Benfica. The Catalans are seeking attacking cover for their senior strikers next season.

Dortmund are prepared to listen to offers for Isak, who has failed to settle in Germany.