Kozak has seen injuries limit him to just 11 league starts in four seasons with Villa and the 27-year-old has only played twice in the Championship this season, both of which were substitute cameos.
The Czech Republican has suffered since breaking his leg back in 2013 and is once again set for another spell on the sidelines.
Bruce announced, according to the Birmingham Mail: “He’s had an ankle operation and is out for the rest of the season. To be honest with you he’s had a really, really bad time.
“He’s a good player but he’s out of contract in the summer. It’s a shame because he’s been hit by so many injuries.”
As the manager indicated Kozak’s contract at Villa is due to expire at the end of the season and the player’s injury record means he is very unlikely to be offered a new deal.
It means the forward has almost definitely played his final game for Aston Villa. Kozak only managed to score four goals during his time with the club, all of which came in his first season.