ST KILDA'S football operations manager Matthew Drain says the form of Justin Koschitzke has been solid but admits the club would like to see an improvement from its key big man ahead of the Saints' crucial clash with Freo on Sunday.

Koschitzke was the subject of criticism following the disappointing loss to Collingwood last week but Drain says he is still crucial to the club's success.

"He's been really important to us in a number of games with his ruck [work in the] forward [line] and what has been most important… is to give us structure," he said at Moorabbin on Wednesday.

"However his performance – and other guys fit into this category as well – at times hasn't been to what Justin would have like or to what we would have liked. He's not Robinson Crusoe there."

The last time the Saints travelled west – in round 16 – Koschitzke did not play due to suspension, and Drain noted that the forward/ruckman was sorely missed in the loss to West Coast.

"That was one of the things that came out of the game; a number of players were even saying 'gee, we missed Kosi in Perth against West Coast two weeks ago'," he said.

"We're back at the same ground – it's a bigger ground, so we think he's going to be very important for us for our structure, and we're sure he will bounce back from last week's performance."

Drain noted that Koschitzke was not the only player that the club was hoping would lift after a poor performance against the Pies, and isolated Nick Dal Santo, despite the silky midfielder playing through an illness in the last two games.

"He was cleared to play and at this stage of the year … every player wants to play. So he wasn't unfit to play, but there's no doubt it (the illness) had some effect on his performance.

"But Nick would want to play better than that anyway as a number of our guys would want to."

Drain would not be drawn on rating the quality of St Kilda's list, saying that the playing personnel would be assessed at the end of the season. But he did foreshadow the club would stick by out-of-form ruckman Michael Gardiner and hot-and-cold goalsneak Stephen Milne.

"We'd like to think Michael Gardiner playing well has got a place on the St Kilda list," he said.

"Milney's kicked 40 goals so it's been a reasonably good year, but he needs some more consistency in the really crunch games.

"We see those guys – historically and even now – as really important parts of our club and important parts of our list, and important parts of us performing this week."