Captain Eustace played 41 league games for the Hornets last season
Derby County want Watford midfielder John Eustace and have renewed their interest in Leicester City's Martyn Waghorn, BBC Radio Derby understands.
Manager Nigel Clough knows Eustace, 31, from a
three-month loan spell at Pride Park in March 2009
And the Rams are eager to bring in a combative midfielder to replace the
retiring Robbie Savage
Clough is also still keen to sign 21-year-old striker Waghorn - a player he
courted without success last season
Waghorn fell out of favour at the Walkers Stadium last term, starting just 11 Championship matches and could become available if the ambitious, big-spending Foxes manage to bring in their summer transfer targets.
Eustace was Hornets skipper last season, starting 41 league games and scoring six goals.