The hosts were beaten 1-0 on home turf by FC Zurich on Thursday, after an away defeat last week, and will look to make a return to winning ways in the league after most recently losing to Celtic.
Match preview
After a third-placed finish in the Scottish Premiership last season, and an eventual defeat in the Scottish Cup final, Hearts headed into the new term with further optimism and a Europa League playoff tie looming.
Robbie Neilson's side kicked off their domestic campaign at home to Ross County and put their first three points on the board with a 2-1 win courtesy of goals from Alan Forrest and Barrie McKay, before being pegged back in the 95th minute against Edinburgh rivals Hibernian after Lawrence Shankland looked to have fired them to a 1-0 win.
The Jam Tarts made a quick return to winning ways in their following encounter at home to Dundee United, dishing out a 4-1 beating as Shankland and McKay were again on the scoresheet alongside Jorge Grant and Josh Ginnelly, before they travelled to take on FC Zurich in the first leg of their Europa League playoff tie and fell to a 2-1 defeat.
On the back of a first league loss of the season against Celtic last weekend, Neilson's side hosted the Swiss outfit on Thursday, but they were unable to overturn the 2-1 deficit, eventually losing 1-0 on the night as Fabian Rohner hit the only goal of the game after Jorge Grant was sent off.
With their place in the Europa Conference League now confirmed, Hearts can turn their attention back to the Scottish Premiership and will aim to make a return to winning ways on Sunday to take their points tally to 10 from five outings.
St Johnstone, meanwhile, make the trip to Edinburgh looking to put a slow start behind them, having collected just three points from their first four league outings.
After avoiding relegation in the playoff last season, eventually beating Inverness Caledonian Thistle 6-2 on aggregate, Callum Davidson's side began the new Scottish Premiership term with home contest against Hibernian and were narrowly beaten 1-0 as Josh Campbell hit the only goal of the game in the dying minutes.
It did not take them long to put a first three-point haul on the board, as Davidson's men won 2-1 away at Motherwell in the following encounter thanks to Stevie May's 94th-minute winner, after Jamie Murphy's opener was cancelled out three minutes earlier, before they faced a daunting trip to Ibrox to take on Rangers.
The Saints were thrashed 4-0 as Malik Tillman, Antonio Colak, Scott Arfield and Tom Lawrence got on the scoresheet, and they were unable to bounce back last time out, losing 1-0 at home to Aberdeen as Leighton Clarkson's second-half goal made the difference between the sides.
Now with just three points from four games, St Johnstone will be keen to turn their form around and avoid another relegation scrap after last season but face a tough test away at one of the league's strongest outfits.
Hearts Scottish Premiership form:
Hearts form (all competitions):
St Johnstone Scottish Premiership form:
St Johnstone form (all competitions):
Team News
Hearts will be without defenders Alex Cochrane and Toby Sibbick for Sunday's contest, as both will serve suspensions after being sent off in their defeat to Celtic, while centre-back Craig Halkett is likely to stay in the treatment room alongside midfielder Beni Baningime.
Given those absences, Stephen Kingsley could again deputise in the middle of a back four alongside summer signing Kye Rowles, with Andy Halliday set to come in on the left-hand side of the defence and Cammy Devlin bound to play at the base of midfield alongside either Peter Haring or Jorge Grant.
Lawrence Shankland will continue to lead the line, having already hit three goals in six appearances following his summer arrival from Beerschot, while Liam Boyce could also play down the middle with the likes of Alan Forrest, Barrie McKay, Josh Ginnelly and Gary Mackay-Steven fighting for spots on the wings.
St Johnstone have an unenviable injury list of their own to deal with, as Christopher Kane, Callum Booth, Tony Gallacher, Cameron MacPherson and David Wotherspoon are all confined to the treatment room, although Celtic loanee Adam Montgomery may be fit to come back into the squad.
Stevie May will be vying to come in and lead the line in place of Theo Bair, having come off the bench in each of their opening four league games and netted the injury-time winner against Motherwell.
Whichever front man is deployed will be flanked by Graham Carey and Jamie Murphy, while, at the opposite end of the pitch, Andy Considine, Alex Mitchell and Ryan McGowan should again line up in a back three.
Hearts possible starting lineup:
Gordon; Atkinson, Rowles, Kingsley, Halliday; Devlin, Grant; Forrest, Boyce, McKay; Shankland
St Johnstone possible starting lineup:
Matthews; McGowan, Mitchell, Considine; Wright, Phillips, Hallberg, Brown; Murphy, May, Carey