Relegation-threatened Livorno have sacked Domenico Di Carlo after just 88 days in charge and re-appointed Davide Nicola.
Virgil van Dijk claims he knows nothing of interest from English clubs and is keen to prove himself in the Champions League with Celtic.
The 21-year-old has only made one appearance for City, as a substitute against Bolton in the Premier League in May 2011.
He has previously spent time on loan with Ipswich, Oldham and Blackpool.
During his time at Boundary Park last season he scored the winning goal against Liverpool in the FA Cup fourth round.
Wabara has represented England at Under-20 level.