Cassisi is listed for a fitness test this week after his rehabilitation from a hamstring injury sustained against Collingwood in Round 14 progressed rapidly.
He would be a logical replacement for the suspended Kane Cornes.
Justin Westhoff is a strong chance to be named in Port’s side to play the Saints after completing his one-match suspension last weekend.
That would mean one other player comes out of the side to make way for him if Cassisi is also named on Thursday night.
Westhoff for Cornes could be the only change if Cassisi isn't cleared fit to a play, but the coaches would be unlikely to make the simple trade off of a shutdown midfielder for a key forward.
Sam Colquhoun has been in hot form in the SANFL while Jack Hombsch also played a strong return game for Sturt on the weekend.
Port Adelaide injury list
Dom Cassisi - hamstring (assess)?
Daniel Stewart - hip (assess)?
Brett Ebert - adductor (1-2 weeks)?
Jarrad Redden - hip (season)
Enemy Lines: The Saints
VETERAN Saints Adam Schneider and Jason Blake are a chance to play against Port Adelaide on Saturday night.
Blake hasn’t played since Round 3 when he suffered a calf injury and Schneider has missed a similar period of time having battled hamstring and illness concerns.
Both players will undergo fitness tests at St Kilda training with saints.com.au suggesting the pair may return through the club’s VFL affiliate Sandringham if not selected for AFL duties on Saturday night.
St Kilda Injury list
Adam Schneider – hamstring (test)
Sam Gilbert – knee (3 weeks)
Beau Maister – hamstring (3-4 weeks)
Justin Koschitzke – calf (3-4 weeks)
Jackson Ferguson – knee (season)
Daniel Markworth – knee (season)
Sam Fisher – toe (season)