Rovers had to wait until the opening of the January transfer window before they could sign Blackman, but he has now signed a deal that keeps him at Ewood until 2011, for an undisclosed fee.
Exciting young striker signs for Rovers
The 19-year-old has impressed during his time on trial with Rovers, he was brought in by former boss Paul Ince, after he worked with him at Macclesfield.