Sporting Lisbon have looked to Jesualdo Ferreira to turn around their poor form after sacking coach Franky Vercauteren less than three months into his tenure.
Belgian Vercauteren, who replaced Ricardo Sa Pinto in October, was dismissed on Monday after guiding the side to just two competitive wins during his time at the club.
The new man in charge is much-travelled former Porto, Benfica, Malaga and Panathinaikos boss Ferreira, who takes over a Sporting side that are 12th in the 16-team Primeira Liga, one point above the relegation zone.
The 66-year-old Ferreira was appointed as the Portuguese club's sporting director last month.
A statement on Sporting's official website read: "The board of directors have announced that Franky Vercauteren will no longer be the coach of the club's first team.
"Sporting would like to thank Franky Vercauteren for his effort and professionalism during his time with the club.
"Furthermore, Jesualdo Ferreira will now become the coach of the Sporting first team, in conjunction with his position as sporting director."
Redknapp said the England midfielder, who has made just four starts and four substitute appearances since joining the R's in 2011, was not involved in his future plans and no longer required at Loftus Road.
Speaking to the club's official website following the decision which takes immediate effect, Redknapp said: "I'd like to thank Kieron for his services to QPR.
"If he can stay clear of injuries I'm sure there's clubs out there that will offer him the chance to play football.
"He wasn't in my plans and I think he's got something to offer someone, so we wish him all the best."
Dyer scored his first QPR goal in their 1-1 draw with West Brom in the FA Cup third round on Saturday.