There was no room for sympathy or sentiment in the dumping of Collingwood forward Paul Medhurst for Saturday's preliminary final against Geelong, according to coach Mick Malthouse.

Dropped for Scott Pendlebury in the only change to the Pies line-up that edged Adelaide in last week's semi-final thriller, Medhurst failed to produce his best since returning from a six-week injury-enforced layoff in Round 13.

From his past 10 matches the 27-year-old contributed just seven goals, a strike rate that pales by comparison with his 50-goal haul last season for which he was rewarded with All Australian honours.

According to Malthouse, Medhurst's position was untenable and that's exactly what he was told.

"The moment we start to get warm and fuzzy inside and start to let our emotions determine the results for picking a player, we're on the wrong track," said Malthouse.

"You've got to make professional decisions."

"Paul knows his form as been very ordinary and, as I said to him during the week, there's nothing wrong with the person - Paul is still a great kid - but he is out of form, out of confidence and he's out of games."

"He'll be judged on his last game."

Malthouse hinted that the door would remain open for Medhurst for a place in the grand final line-up should the Magpies happen to get past the Cats on Saturday night.

Medhurst has been named in the centre for Collingwood's VFL side which will contest a preliminary final against North Ballarat at Port Melbourne on Saturday afternoon.

"Paul needs to demonstrate tomorrow and will be judged on his performance tomorrow," Malthouse said.

"We need to pick our best side for the occasion and we think the side picked is the best form side we can take in against Geelong."