Craig Morgan and Ben Pringle have rejected new contracts at Rotherham and will leave the club on free transfers.
Saido Berahino can leave West Brom "if the deal is right", says manager Tony Pulis.
Almen Abdi has confirmed that talks have opened about a permanent switch to Watford from Udinese.
The midfielder was one of 10 players to arrive from the Serie A side last summer shortly after the Hornets' takeover by the Pozzo family, who control both clubs as well as Spanish side Granada.
Abdi has proved a successful addition having made 24 league starts and scored eight goals, the third-highest among Watford's ranks behind 19-goal top scorer Matej Vydra, another Udinese loanee who is also in talks to turn his season-long stay into a permanent deal.
Abdi, 26, is giving little away as to the progress of the discussions, but told the Watford Observer: "Yes (talks have started) but I can't say anything about it at the moment. We have talked a little bit.
"Of course I like the football, I like being near London, I like the club and the guys here but I can't say anything because it is too early."
Watford are currently third in the Championship and out of the automatic promotion places on goal difference.