Derby County's Championship rivals are making transfer moves ahead of the new season, with Southampton and Burnley securing deals. The transfer window officially opens on Monday, June 15, with business beginning to take shape across the Championship. Southampton have announced the permanent acquisition of Daniel Peretz from Bayern Munich, with the shot-stopper penning a four-year deal. Peretz initially arrived at St Mary's on loan in January and made a strong impression as the Saints embarked on a 21-match unbeaten streak, recording eight clean sheets as they progressed to the Championship play-off final. Burnley have brought Jiaming Zhang into their Under-21 squad on a one-year deal. The 19-year-old previously featured for Liaoning Tieren in China's second division before receiving an invitation from Bayern Munich to join their World Squad Initiative 12 months ago. This was followed by a stint at Serbian side FK Voždovac, where he scored three goals in four matches for their Under-19s. Sheffield United are preparing for additional interest in England Under-21 midfielder Sydie Peck, as another contender is reported to have entered the race. According to The Sheffield Star, West Ham United have had their eye on the midfielder since January, and should they sell Mateus Fernandes as anticipated this summer, they would have sufficient funds to put forward an attractive bid for the 21-year-old. The Star also reports that Nottingham Forest and Brentford have shown interest, while Peck remains contracted at Bramall Lane until at least 2028, with the possibility of an additional 12 months owing to a clause in his contract.