Sometimes a particular opponent has your number and for Dundee United that is probably the best way to interpret Saturday's defeat at the hands of the team that beat them in last season's Scottish Cup final.

The alternative, ahead of the remarkable month of football that will see them meet only one other team in three season defining matches is to have considerable reason to beware the ides and every other part of March.

All the moreso because, in spite of the irrefutable evidence that the right decision was made in business terms, the sense among supporters is that they and their team have been betrayed when on the point of achieving greatness.

Admittedly there was much amusement generated throughout Scottish football when Radoslaw Cierzniak, their regular goal-keeper, dared to articulate their dream when pointing out, a month or so ago, that they had a chance of winning a treble this season.

However that only made it seem all the more symbolic that his first absence of the season coincided with their first back-to-back defeats of the season, suggesting the sort of loss of momentum that was feared when Stuart Armstrong and Gary Mackay-Steven were sold to the team they will spend next month competing with.

Easy to conclude, then, that United are now about to enter a period of decline at the worst possible time, which is why it might be preferable to accept that they have a particular problem with this St Johnstone team that has now beaten them in six of their last seven meetings in little more than a year, allowing an otherwise free-scoring team to put just three goals past them in that period.

Signed since the cup final defeat Jaroslaw Fojut has been involved only for this season's three meetings he is entitled to deflect such questioning, but in attempting to choose his words carefully on the subject he offered some insight into the fact that there are opponents who make United feel uncomfortable.

"Obviously we play against a team who just eh... let me say something not controversial," said the experienced Polish central defender.

"No... we just want to survive the game and score a goal."

That hints at a tentative approach which allows this vigorous St Johnstone side to seize upon and the clear relish with which they did so was reflected in the analysis offered by rival centre back Frazer Wright, who had been part of a defence that allowed the home side a solitary chance over the 90 minutes.

"It seems that if we can score first against them, then we can get into their heads a wee bit," he said.

"The time they beat us this season, they scored first against us, so I think when our first goal went in we had a big advantage."

"Today they changed their midfield and their shape. They don't normally do that so they were definitely thinking about us.

"After we got the first goal, they seemed to argue amongst themselves a bit. It means we were doing our jobs and it was working correctly for us. We just took advantage of that."

They did so from the outset and maintained the upper hand pretty much throughout, debutant United goal-keeper Michal Szromnik forced into an excellent save moments before his mistake which allowed Michael O'Halloran to register the opening goal that put the visitors in charge.

Admittedly the ball dipped and swerved slightly to Szromnik's left, but he had a clear view of it all the way and should not have been beaten.

His defenders were more culpable for the second, reacting too slowly in allowing Dave Mackay's cross from midway inside the United half on the right to travel all the way to where O'Halloran was ready to despatch it inside the six yard box.

However what was an even greater concern for United than any defensive issues was the absence of creativity, the departures of Armstrong and Mackay-Steven, who have started so well at Celtic, seemingly exacerbated by the decision to leave Charlie Telfer and Aidan Connolly on the bench.

In terms of what is to come it places an additional premium on tomorrow night's meeting with Inverness Caledonian Thistle which looks as if it will now go a long way towards deciding which of them finishes third in the table, Celtic and Aberdeen now looking to have stretched their respective advantages beyond the realistic reach of both.

Having lost just one match at Tannadice this season before Saturday's United need, at the very minimum, to avoid defeat if they are to avoid looking as if the momentum generated in the first six months of this season has all dissipated as a result of having key cogs removed from the machine at the critical moment.

For now, though, they would be better to persuade themselves that they merely have a bit of a hang up when it comes to facing these Tayside neighbours.