Date of Birth:30/05/1989
Height:6' 4" (193cm)
Weight:12st 13lbs (82.0kg)
Previous Clubs:Lazio, Lazio
Kozak admits he was devastated when he was told he had broken his leg in a training ground tackle at Bodymoor Heath on New Year's Day 2014.
But the striker says his lowest moment - and one where he questioned whether he'd ever be back - was when he was forced to undergo a second operation.
He had gone under the knife immediately after his initial diagnosis but after seven months of arduous work to get back to full fitness - he received the news that all was still not well with his fibula.
So he flew over to Italy for a follow-up procedure.
He stayed there rehabbing in the company of family and friends and by February 2015 he was back in training with the U21s - running, shooting, passing - in fact, everything that didn't involve contact.
Some weeks later, he returned to full training and while he wasn't able to get a runout due to Villa's precarious position in the Barclays Premier League table, likeable Libor saw light at the end of his tunnel.
Kozak started his career in 2001 with Czech club Slezsky FC Opava, first playing with its youth teams before being promoted to the first team in 2007.
Considered a promising talent, Kozák was a prolific goalscorer in the Czech Second Division with Opava.
In October 2007 he scored his first hat-trick, coming in a 5-1 Opava win against FC Zenit Caslav in the Second Division.
At the end of the season, Italian giants Lazio came calling and Kozak accepted a move.
After a season at Lazio, the club loaned him to Serie B side Brescia for the 2009-10 season, to gain experience and regular playing time.
He returned to Lazio and enjoyed steady progress in Rome, bagging a competition-leading eight goals in the 2012-13 Europa League.
It was this that persuaded Paul Lambert to snap up Kozak, who rewarded him with important goals in his first season against Norwich, Cardiff, Southampton as well as the only goal in a defeat against Stoke.