The Championship outfit had been on the verge of signing the 22-year-old before a loan agreement broke down before the end of the summer window.
Not registered to play in La Liga, Collado has been left in limbo, waiting for the start of 2022 to arrive so that he can secure a move elsewhere.
According to reports in Spain, Sheffield United are one of a number of clubs who are interested in sealing a deal for the wide player.
While Collado's contract is due to expire in 2023, Barcelona are allegedly against including the option of a permanent transfer in any proposal. body check tags ::