The 25-year-old Johansson joined Blackburn in 2001 from German side Nuremberg and has made 86 league appearances for Rovers.
Kenny Lunt will also be allowed to leave Crewe in the summer and could be set for a move to Elland Road.
The 25-year-old has been at Gresty Road his whole career, making over 350 appearances but with only one year left on his contract will not sign a new deal. Crewe's transfer policy will not allow Lunt to leave on a free.
Defender Raffaele Schiavi has emerged as a target for the Whites.
The 19-year-old currently plays for Salernitana where he has attracted the attention of Leeds who are believed to be considering a move for the player.
Leeds are keen to add defensive options for next season and have also been linked with Everton duo David Weir and Gary Naysmith as well as Blackburn’s Gray, Short and Johansson .