SEASON-DEFINING moments aren't always planned, and can come in the form of spontaneous acts of bravery or an inspiring come-from-behind victory.

For St Kilda coach Ross Lyon, his side’s season-defining moment came in the lead-up to the round 13 clash with Fremantle when he dropped Nick Dal Santo and Stephen Milne.

The Saints won a tough contest and the two stars were quickly reinstated. But Lyon says the hard line taken at the selection table is part of the reason the Saints are now one of just four teams still in the premiership race.

"It’s easy when your proven performers aren’t playing well to just keep them going. Sometimes it is the soft options. It could have been more than two dropped," a reflective Lyon said in the lead-up to Saturday night's preliminary final against Hawthorn.

"All of a sudden everyone on the list thought if they do the right thing and produce, they are going to be picked. Sometimes it is as simple as that."

Lyon said there were other reasons for St Kilda's form turnaround after heavy criticism in the first half of the season.

"There were a number of contributing factors. What gets lost is we were 4-3 when we played Richmond and had a really courageous hard-fought win," he said.

"That day we lost five players and it really unbalanced us for a little while. We changed our midfield mix a bit and as coaches we took some responsibility for integrity of selection and our confidence was built out of our actions.

"I really felt from the president through [to the players] we were united, we worked hard, we put our shoulder to the wheel and turned it gradually until our confidence continued to build on our actions."

A selection policy rewarding endeavour above all else has seen the Saints give opportunities to younger players such as Jarryd Allen, Robert Eddy, Clinton Jones and David Armitage – who all played in the semi-final win over Collingwood.

"Ultimately players pick themselves, so young players need to put performances on the board and then some injuries and lack of form opened up those opportunities.

"It’s probably something that's been missed from the weekend. [To have] six players with under 30 games is significant for St Kilda and I thought it is something that has flown under the radar."