The experienced trio of Craig Cathcart, Tom Cleverley and Dan Gosling are in talks about new deals with Watford.
The Hornets have said "there should be no rush" in determining the futures of Cathcart, 34 and Cleverley, 33, who are out of contract this summer.
And while Gosling, 33, had his contract terminated by mutual consent in March after sustaining an Achilles injury, a new deal remains possible.
Meanwhile, Britt Assombalonga and Leandro Bacuna have been released.
Assombalonga, 30, returned to the club in January and made 11 appearances, but the additional 12-month option on his contract has not been triggered.