HITC Sport understands from sources close to the club that Watford have agreed a deal to sign Werder Bremen defender Sebastian Prodl.
The 27-year-old is out of contract at Bremen this summer and has turned down the offer of a new deal to stay at the Weserstadion.
Prodl has impressed at Bremen since arriving from Sturm Graz back in 2008.
The Austrian international has made over 150 Bundesliga appearances for the club and his availability on a free transfer has alerted a number of clubs across Europe.
The likes of Serie A sides Lazio and Fiorentina, along with Turkish outfit Besiktas, have been credited with holding an interest in Prodl, but Watford are set to win the race for his signature.
Leicester City have also shown an interest in Prodl, but Watford have moved quickly to agree a deal with the free agent to make him their first signing of the summer.
A number of fresh faces are expected to make their way to Vicarage Road during the upcoming transfer window as the Hornets seek to piece together a squad capable of competing with the Premier League elite.