Everton are said to be tracking Stuttgart defender Timo Baumgartl.
Baumgartl has made 29 appearances as the 2.Bundesliga side aim to return to the top flight and is attracting interest from the Blues ahead of this summer.
Reports in Germany claim that Ronald Koeman is already facing competition for the 21-year-old from Watford, who will part with Walter Mazzarri on Sunday.
According to SportBild, the Premier League duo are set to battle it out for Baumgartl, who has represented his country up to under-21 level.
Koeman’s interest in the highly rated centre-back and one-time Arsenal target comes as he bids to revolutionise Everton’s defence during the close season.
With Ramiro Funes Mori injured, an ageing pairing of Phil Jagielka and Ashley Williams have remained ever-presents in the final months of the campaign.