GETTY Libor Kozak played for Aston Villa during pre-season this summer

Kozak, 26, is reportedly free to leave Villa after failing to make an impact at the club - partly due to injury. He has scored just five goals since his £7million arrival from Lazio two summers ago.

A broken leg hampered his debut campaign in English football and fitness worries meant he didn't get a run-out at Villa Park last term. And it is understood Celtic are prepared to offer him an exit, although they face competition from German side Mainz to land the forward, claim the Times.

Celtic manager Ronny Deila is seeking new recruits ahead of an expected Champions League campaign. The Hoops take a 3-2 advantage into the second leg of their playoff qualifying tie with Swedish side Malmö tonight.

GETTY Aston Villa are hoping to sign Adem Ljajic from Roma this week