Arsenal and Manchester United have reportedly been put on alert after learning that German side Borussia Dortmund are willing to let defender Mats Hummels leave at the end of the season.

The 26-year-old has been linked with a move to the Premier League in the past, but Dortmund have always resisted offers for one of their star assets.

However, with Jurgen Klopp's side expected to miss out on Champions League football for next season, Dortmund may now be forced to sell, reports ESPNFC.

Hummels, who joined Dortmund permanently from Bayern Munich in 2009, is also a German international, with 38 caps to his name.