CARLTON has been dealt a blow ahead of Thursday night's clash at Marvel Stadium against St Kilda with Zac Fisher a late withdrawal.

Fisher, who hasn't played since suffering a syndesmosis injury in the club's round one loss to Richmond in March, was due to make his return against the Saints.

FOLLOW IT LIVE Blues v Saints face off at Marvel

But he is out with illness and has been replaced by youngster Sam Philp, who made his debut in last week's thrilling win over Essendon.

St Kilda will go in as selected with skipper Jarryn Geary a confirmed starter after recovering from a hamstring strain.

Meanwhile, there was a COVID-19 scare at Marvel Stadium during the week with a security contractor testing positive.

STATEMENT Contractor tests positive

The contractor has not worked since his shift on Monday and had no contact at any time with any sealed football-related areas.

As the AFL continues to manage an unpredictable football landscape and juggles a shifting fixture, this game was suddenly moved to Thursday night and Marvel Stadium when Richmond's clash with West Coast was postponed due to COVID border restrictions.

It was a twist of good fortune for the Saints who have five wins and two losses from their past seven games at the venue, while Carlton has the opposite record at Marvel with just two wins from its past seven.

Adding intrigue to this battle is the form of small forward Dan Butler. 

Butler, the ex-Tiger, was hopeful of being traded to Carlton at the end of last year, but the Blues' interest faded significantly when Sydney goalsneak Tom Papley established himself as the club's priority trade target. While that fell through, Carlton still managed to grab Jack Martin from Gold Coast and Eddie Betts from Adelaide.

Butler landed at St Kilda and hasn't looked back, turning it on against his former club last week. Will he make Carlton regret that decision tonight?