Sept 3 (Reuters) - Red Bull boss Christian Horner expressed concern on Friday that rivals Mercedes could block a bid to bring Alexander Albon back to Formula One next season, with seats opening up at Alfa Romeo and Williams. Mercedes are also keen to place their newly-crowned Formula E champion Nyck de Vries and Williams, who are interested in British-born Thai driver Albon, use the German manufacturers" engines. "We"re working hard to get him (Albon) a seat," Horner told Sky Sports television at the Dutch Grand Prix. "I really hope that Mercedes don"t block his opportunity at Williams. That would be a great, great shame." Horner explained that would be because of his links to Red Bull. "It would be a great shame if a driver were to pay the penalty for that. Hopefully that won"t come to play," he added. If no race seat was forthcoming, Albon would continue in a test and reserve role, added the boss. Albon, 25, drove for Red Bull last year but lost his seat to Mexican Sergio Perez, now confirmed for 2022 alongside Max Verstappen. The Thai has since raced in the German Touring Cars (DTM) series. Horner saidWilliams and Alfa Romeo had expressed "a lot of interest" in Albon and hoped something could be sorted within days. "I think his preference would be Williams," he added. "But obviously there"s a few hurdles. He"s had about four phone calls telling him not to go there from the team next door (Mercedes). I told him to ignore them." DRIVER SHAKE-UP With Alfa Romeo"s Kimi Raikkonen retiring at the end of the season and Williams" George Russell lined up to replace Valtteri Bottas at Mercedes, Formula One is braced for a driver shake-up anyway. Bottas is expected to replace Raikkonen but there are doubts about the second Alfa seat, currently occupied by Italian Antonio Giovinazzi with engine provider Ferrari having a say on who fills it. Albon is driving an AF Corse Ferrari in the DTM with sponsorship from Red Bull"s AlphaTauri. Williams boss Jost Capito has worked closely with Red Bull in the past while head of Volkswagen Motorsport. Asked whether Albon might be released from his Red Bull contract, Horner said there was flexibility. "We"ll accommodate whatever we can to ensure that he"s back in a race seat next year," he said. De Vries has also been linked to Williams and Alfa but Mercedes motorsport head Toto Wolff said Albon was key to events. "At the moment it revolves around Alex Albon who, as Christian says, deserves a seat," said the Austrian. "He"s a really good kid and he"s probably the main protagonist in the moving chairs." "Nyck has a guaranteed seat in Formula E with us and I"m in two minds. I wish him to be in Formula One but I don"t want to lose him for our Formula E campaign." (This story refiles to change day in first paragraph)