Watford are among the clubs interested in Benfica defender Branimir Kalaica.
Leeds and Celtic are also keen on the Croatian central defender ahead of next season.
Watford will be in the market for a new centre half ahead of the 2020/21 campaign, while Leeds are already planning to strengthen their squad ahead of what looks like a return to top flight football.
Croatia Under-21 international Kalaica joined Portuguese giants Benfica from Dinamo Zagreb in 2016 on a free transfer.
The ball-playing central defender notched on his Benfica debut against Boavista in 2017, but in the last couple of seasons he has been playing for Benfica B in the second tier of Portugal.