Winnall spent last season on loan at the Rams and earned plenty of admirers despite missing the second half of the season with injury.
Winnall’s future looked set to come at Pride Park but Gary Rowett’s departure to Stoke City will mean a change of the guard at Derby who are in talks with former England star Lampard about taking the managerial role.
That means uncertainty for Winnall who has now returned to the Owls for whom he has struggled to make an impression since signing in January 2017.
Sheffield United, meanwhile, are confident of keeping hold of young striker star David Brooks despite the likelihood of interest from clubs in the Premier League.
Brooks would likely command a fee in the region of £15m.
But Hull City face a real battle in attempting to retain the services of both Michael Dawson and Seb Larsson who could both leave the KCOM Stadium this summer.
Leeds United continue to be linked with a host of players but Hull striker Abel Hernandez, Swansea City centre-back Kyle Bartley and Manchester City goalkeeper Angus Gunn remain the club’s three main targets though there are suggestions the Whites could be about to sign Crusaders winger Gavin Whyte.
In League One, Barnsley midfielder Stevie Mallan is attracting the interest of Hibernian.
Mallan joined the Tykes from St Mirren for around £250,000 and now Neil Lennon’s side want to take the 22-year-old back to Scotland.
The Tykes are currently without a manager and Wycombe Wanderers boss Gareth Ainsworth is the latest name to be linked with the post following the sacking of Jose Morais.
Former Peterborough United boss Grant McCann is also being strongly linked with the role.