Manager Peter Houston has told his Dundee United side to improve their home form and eliminate the mistakes which have contributed to recent poor results.
United lost 2-1 at Hearts on Sunday after Brian McLean and Gavin Gunning contrived to fail to clear allowing Ryan Stevenson to score before the Hearts midfielder netted a penalty.
The visitors replied through Keith Watson, but were unable to breach the Hearts defence again as they fell beneath the Edinburgh side in the Clydesdale Bank Premier League table.
That result came a week after seeing a three-goal lead slip against Inverness and a point rescued with a stoppage-time penalty and Houston has called for United to tighten up and add to their two home wins this term in Wednesday's Tayside derby.
``St Johnstone's a tough match, but we have to start putting a run together with regards to our home form,'' Houston said. ``Our away form has been good. We played well (at Hearts) and lost the match, but we have to make sure we start a wee run at home.
``We have to clear our heads of our result and try to get a result against St Johnstone on Wednesday.
``We have to really, really stop giving soft goals away. We have to make sure we cut out the errors that we're making.
``We can play as good football as any team in the league in my opinion, out with Celtic.''
Defender Sean Dillon is unlikely to return from a thigh injury before the winter break, and after the error which led to the opening goal at Tynecastle, Houston was asked if he would consider shifting captain Jon Daly to centre back.
Daly, a striker, played in defence earlier in the season, but along with Johnny Russell is part of a potent strike-force.
Houston said: ``No. He's near the top of the scoring charts already with eight goals, having played a few times (in defence).
``Brian McLean's been playing excellent the last few weeks and I don't blame Brian for losing the match.
``He made an individual error, he put his hand up, but it cost us. Wee individual errors are costing us.''
Manager Steve Lomas has told his St Johnstone fringe players to show their ability if given an opportunity in the next three matches.
Saints, seeking an end to a four-match winless run in the Clydesdale Bank Premier League, play Dundee United before matches with in-form Inverness and bottom club Dundee.
The Perth men are part of a pack chasing a place in the top six ahead of the winter break and a two-week hiatus and may have to negotiate the festive fixtures without Chris Millar.
Midfielder Millar was withdrawn from Saturday's 2-0 loss at Aberdeen with a groin injury and replaced by Paddy Cregg, who could start at Tannadice.
``Chris has tweaked his groin, so we'll have to wait to assess him and see how he is for the busy Christmas period,'' Lomas said.
``It gives somebody else an opportunity to step in and show their worth.''
With Dundee now in the top-flight, the Tayside derby may have less significance for United, but for St Johnstone victory over their near-neighbours would provide a welcome fillip.
Lomas maintains his side can defy their recent run against a United side full of talent.
``Any team can beat anybody on any given day,'' Lomas said.
``It'll be tough because they're a decent team and they've got decent players, (Johnny) Russell, Jon Daly, (John) Rankin.''