Collingwood coach Mick Malthouse is certainly not reading too much into St Kilda's inept performance against Geelong in last week's qualifying final - ahead of Saturday's semi-final clash at the MCG.

The Saints were simply steamrolled and the final margin of 58 points flattered Ross Lyon's team as the Saints' coach himself admitted after the game.

However Malthouse - whose team is the only one to have beaten Geelong this season - is all too aware of how teams can look ordinary against the reigning premier only to then perform much better when pitted against lesser opposition the following week.

"A lot of clubs have bad games against Geelong but their previous form is solid," Malthouse said of St Kilda.

"We'd be silly to look at the Geelong game and say that's the way they (St Kilda) play because they don't and they beat Essendon, Adelaide and Fremantle before that so that is good form."

And Malthouse said history was littered with sides copping a hiding and bouncing back the following week - such as last year when North Melbourne lost to Geelong by 106 points in the qualifying final only to bounce back and beat the Hawks in the semi-finals the following week.

"For one reason or another someone gets a hiding one week and they find something special for the following week," he said.

"We all say 'why does it happen' but we have all played the game and we all know sometimes you have a disastrous game but the following week you grit your teeth a bit harder or something happens your way and you become a better player."

"I don't know why that happens but that is why I dismiss bad games (from a team) that are inconsistent with their previous games."

And although the Pies have won their past three games against the Saints - Malthouse is aware his team's biggest margin in any of those games is just 14 points - the last time the two teams met in Round 19 this season.

"We have been pretty competitive against St Kilda (recently) but they have all been close games," Malthouse said on Wednesday.

"So we can't get too overly enthusiastic about it (winning the past three games against St Kilda) but by the same token we take some confidence out of having played well against them recently."