The player arrives on a free transfer and Rovers have the option to extend the deal should they wish to at the end of the first initial twelve months.
The striker will not be available for Saturday’s clash with Arsenal at Ewood Park as the paperwork was not completed in time.
The Zimbabwe international had been training with Sam Allardyce's side as a free agent recently, Allardyce said earlier: "We are trying to sign him on a contract because of his wealth of experience.
"He has trained with us a few days. He has shown us that we think he will be okay to play for us in the Premier League. So we are trying to sort something out."