Blaha, a former Czech Republic Under-21 international, has signed until the end of the season after the red tape blocking his move was cleared up in time for the 5pm signing deadline today. The 26-year-old free agent, who left Slovan Liberec last year, will be in the Aberdeen squad to face Inverness Caledonian Thistle on Saturday.
Jimmy Calderwood said: "The lad came back to Aberdeen and has agreed to sign a short-term deal. This gives us an opportunity to have a look at him and for him to find out more about us. If he does well, there will be an option to extend his deal. We have been impressed with what we have seen so far and the lad has good experience as he has played in the Champions League."
The striker was a target for Calderwood last summer before the player decided to stay at Liberec, but he left the Czech club last year.
Meanwhile, there is news today that Aberdeen are interested in Belgian goalkeeper Erwin Lemmens. The 28-year-old seems set to leave Espanyol in the summer after the club decided against offering him a new deal. He has fallen out of the first team picture with the Primera Liga outfit following the arrival of Cameroon international Carlos Kameni, but with Celtic, Norwich City and Southampton also interested, and three 'keepers on the Dons books in the summer, it would be a major surprise to see the Dons successfully sign the Belgian.