It would be the Elland Road club’s biggest signings in over 15 years if the striker agrees to drop his £40,000 wages to around £35,000.
Vydra is expected to slip out of the starting line-up if he stays at Derby following their capture of Peterborough United’s Jack Marriott and continued interest in Sheffield United target, Ipswich Town forward Martyn Waghorn.
Leeds are also said to have had a £1.2m bid for Poland international defensive midfield player Taras Romanczuk rejected by Jagiellonia Bialystok.
The Elland Road club, already said to be eyeing Middlesbrough striker Patrick Bamford, and Hull City have also been linked with a move for striker Mbaye Diagne, who is valued at £3.6m by his Turkish club, Kasimpasa.
Bournemouth have also shown interest in the 26-year-old Diagne, who was born in Senegal and was signed by Italian side ASD Brandizzo as a youth player before moving to Juventus in 2013.
Italian and Russian clubs have also shown interest in the forward.
The Tigers face competition from Millwall in their attempt to sign Barnsley’s Wales striker Tom Bradshaw, 25.
Leicester City could be back in for Middlesbrough’s Ben Gibson if they sell Harry Maguire to Manchester United, who have already had a £65m bid for the England World Cup star and former Sheffield United and Hull City defender rejected.
The Foxes made an unsuccessful move for Gibson last season.
Sheffield Wednesday goalkeeper Keiren Westwood is a target of both Premier League side Southampton and Stoke City.
Sunderland look to be the only club left interested in signing Bradford City striker Charlie Wyke after long-time favourites for his signature, Bolton Wanderers, shelved their interest in the player.
Target man Wyke is due to return to training next week after a knee problem and the Black Cats are preparing to make a final bid, understood to be around £1m for the for the 25-year-old, who is in the final year of his contract.
Doncaster Rovers’ left-back Tyler Garratt, 21, is set to join AFC Wimbledon if he impresses in a friendly for them against Boreham Wood.
Barnsley are set to sign defensive midfielder Australian Kenneth Dougall, 25, from Sparta Rotterdam after he completes a medical at Oakwell.
Former Barnsley central defender Alfie Mawson looks set to move from Swansea City to Burnley.