Hibernian defender Ryan Porteous is travelling to Watford after the Easter Road club accepted a bid in the region of £450,000.
The 23-year-old is out of contract this summer and had turned down the offer of a new deal.
Porteous has made more than 150 appearances for the Easter Road club and made his Scotland debut in September.
Hibs are still in discussions with Millwall over striker Kevin Nisbet.
The English Championship side, who are third in their division, made a bid of more than £2m for the Scotland international on Wednesday and it is still under consideration by Hibernian owner Ron Gordon.