Saints bounced back from a demoralising 4-1 home defeat to Ross County in January to embark on a four-game unbeaten run that also saw them shock Celtic and snatch a place in the Scottish Communities League Cup final.
But recent defeats to Hibernian and St Johnstone have halted their run and taken the fizz out of soaring confidence in the Saints changing room - as well as leaving them with a huge nine-point gap to bridge to make it into the top six.
They now face Hearts in a dress rehearsal of their Hampden decider - scheduled for March 17 - when they host the Jambos in Paisley.
But with just six games left until the league split, Saints number one Samson believes a victory over John McGlynn's men could yet keep their ambitions of breaking into the top half of the table for the first time in the SPL era alive for another week.
"The top six is still a live issue for us. Just look at Ross County. They were only a point above us when we played them here. They beat us 4-1 and have not been beaten since," he said.
"Now they are sitting three points from second place. So if we go and do the same as that - push ourselves on, get wins on the bounce, put pressure on teams - then we can get in the top six.
"I'm not saying we have not made it difficult. We've made it very difficult for ourselves, but it is possible.
"In saying that, it's now or never. The games are running out. We have to win to have a chance to do that.
"If we don't, it will just be a case of finishing as high as we can."