"I would like to get back playing," he told BBC Radio Wales. "In my own mind, I have pencilled in March.
"I've read in the papers and seen on the TV that my career is over and that's a bit unfair. I haven't been too pleased with that because it certainly isn't the case."
He added: "I want to contribute to Sheffield United this season and if I can do that come the latter end, then that's great.
"All I am thinking about is getting this back right and continue playing."
United boss Kevin Blackwell said the midfielder could take up a management or coaching role with another club.
Blackwell said: "I am getting used to being without him as a player."
Speed, who has won 86 caps for his country, started his career with Leeds in 1988 and moved to Everton for �3.5m in 1996.
Two years later he joined Newcastle for �5.5m and he then signed for Bolton in the summer of 2004.
Four seasons followed at the Reebok before he joined Sheffield United in last season's January transfer window.
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