The visitors currently find themselves two points better off than their hosts, who occupy the relegation playoff place with two games remaining after both suffering defeats at the weekend.
Match preview
With two games remaining in the Scottish Premiership relegation group, St Johnstone head return to McDiarmid Park on Wednesday desperate to escape the bottom two, having failed to narrow their gap to safety last time out.
Aiming to again preserve their top-flight status this term, the Saints finished the regular season in 10th spot, narrowly above the bottom two having earned 31 points from their 33 matches, but they have been unable to add to that tally in three attempts since the split of the division, firstly hosting Hibernian and suffering a 3-1 defeat late last month.
A trip to Aberdeen then followed, and Craig Levein's side would drop into the relegation playoff place following a 1-0 defeat, as Bojan Miovski netted the only goal of the game from the penalty spot, before they most recently met already-relegated Livingston on Saturday and set out to leap straight back out of the bottom two.
The Saints led for the majority of that contest, thanks to Adama Sidibeh's opener, but the hosts drew level through Cristian Montano in the 72nd minute, before Andrew Shinnie sent them home empty-handed with the decisive goal deep into injury time.
That result saw St Johnstone remain two points behind Wednesday's hosts heading into their final two games of the season, and they will aim to leap out of the relegation playoff place ahead of the last day with a crucial return to winning ways at McDiarmid Park, while knowing a defeat would see them condemned to a playoff.
Their visitors, meanwhile, travel to Perth in search of a victory which would guarantee their automatic survival in the Scottish Premiership, having improved their standing and leapfrogged the hosts after the league's split.
After the 33-game first phase came to its conclusion, Ross County sat a point behind Wednesday's opponents in the bottom two, having only picked up seven wins while suffering 17 defeats along the way, albeit with one of the victories being over title-chasing Rangers in the final round.
Like St Johnstone, the Staggies endured a losing start to the relegation group in the fight for survival, falling to a disappointing 2-0 defeat away at basement side Livingston, before they managed to make an important return to winning ways at home to Hibernian at the beginning of the month with Simon Murray drawing them level early on before Jordan White snatched all three points with the decisive goal in the 88th minute.
Aiming to build on that result and move further clear of the bottom two, Don Cowie's side most recently hosted Motherwell on Saturday, and after drawing level at a goal apiece through Murray inside the opening 15 minutes, they would eventually suffer a 5-1 beating, with Blair Spittal going on to net a brace alongside goals from Paul McGinn, Davor Zdravkovski and Harry Paton.
While they were unable to extend their cushion over St Johnstone in that game, Ross County do head into the penultimate game with a two-point lead and will bid to guarantee a finish above the bottom two and another campaign in the top flight with a victory on Wednesday.
St Johnstone Scottish Premiership form:
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Ross County Scottish Premiership form:
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Team News
Despite the disappointing defeat to Livingston last time out, St Johnstone are unlikely to make many changes to their starting XI on Wednesday, with Sven Sprangler and Ross Sinclair remaining sidelined by injuries.
In a 4-2-3-1 shape, Adama Sidibeh will continue to lead the line, having scored his third goal of the season at the weekend following a February arrival in Perth, while Stevie May, Graham Carey and top scorer Nicky Clark should again line up in an experienced and dangerous supporting trio.
Matthew Smith and Max Kucheriavyi will both fight to return to the midfield from the outset, after Cameron MacPherson and Daniel Phillips were preferred on Saturday, while Liam Gordon and Ryan McGowan will again fight off competition from Andy Considine to partner up at the back.
Ross County have several selection concerns of their own to contend with, as Scott Allardice, Ross Callachan, Max Sheaf and Dylan Smith are confined to the treatment room while key centre-back Jack Baldwin will serve a suspension for an accumulation of yellow cards.
In his absence, Huddersfield Town loanee Loick Ayina will likely come in from the start to join Will Nightingale and Ryan Leak in a back three, while Connor Randall and Eli King should continue their partnership in midfield with Yan Dhanda operating ahead in support of a front two.
Simon Murray will again be relied upon to lead the attack, having scored in back-to-back games and netted six in the last seven outings to take his tally to 20 goals for the season in all competitions and 13 in the Scottish Premiership, while Jordan White and Eamonn Brophy will fight to join him up top.
St Johnstone possible starting lineup:
Mitov; Wright, McGowan, Gordon, Keltjens; Smith, MacPherson; Carey, Clark, May; Sidibeh
Ross County possible starting lineup:
Laidlaw; Ayina, Nightingale, Leak; Efete, Randall, King, Reid; Dhanda; Murray, White