Czech Signs Today
The 26-year-old met Allardyce at St James' Park yesterday afternoon after flying in for a medical and talks.
Newcastle fought off competition from Borussia Dortmund, who believed they had done enough to sign the Czech last week when he showed interest and flew to Germany.
But it just shows you can never say for certain you have captured a player until he signs on the dotted line.
Mark Viduka and Joey Barton have already arrived through the doors at St James' and suddenly there is high expectation again on the streets of Tyneside.
As for the other defenders to arrive - Allardyce released Titus Bramble, Craig Moore, Oguchi Onyewu and Olivier Bernard within days of his arrival, and has been busily scouring the market for replacements ever since.
He was keen to persuade Israel international Tal Ben Haim to follow him to Tyneside from Bolton, but ultimately lost out to Chelsea.
Liverpool's Sami Hyypia and Marseille captain Habib Beye are among his remaining targets.