Did we get too excited, too soon about Hearts?

Little over a month ago, observers outside of Scottish football were looking in at a potential storybook season unfolding at Tynecastle.

A statement 3-1 win for leaders Hearts over reigning champions Celtic had opened up an eight-point gap at the Scottish Premiership summit. A title challenge was on.

Six games later, the Edinburgh side's advantage has vanished, with a trip to Parkhead looming on Sunday and Celtic having played a game fewer.

Victory in the east end of Glasgow will refuel talk of a title push from Derek McInnes' side, but the past month has served as a reality check.

Wednesday's draw with Kilmarnock was a fourth in the last six games and was greeted with a little bit of discontent from the stands.

"There was a bit of booing, probably borne from frustration," said former Hearts winger Neil McCann on Sportscene.

"They've not won since 1 November and Celtic are putting a bit of pressure on. They play both the Old Firm and having the Edinburgh derby coming up, too."

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Why past month is harsh reminder

The Hearts support made a habit of belting out 'we shall not moved' throughout a stunning start to the campaign. There was even footage of head coach McInnes joining in.

Carried away too early? That is certainly what some will say, but why shouldn't those scenes have unfolded?

Nobody has the right to police the emotion within a fanbase, although the past few weeks have been a harsh reminder of the scale of the task when it comes to a non-Old Firm side maintaining a lead, never mind winning a title.

Of course, nothing is ruled out at this stage. Yes, Hearts are now level on points with an unconvincing Celtic, but McInnes' men are still top.

They have only lost once in 15 games. They have still scored six more goals than the second-placed Parkhead side. They are still nine points clear of Rangers.

Although it feels unlikely given their current run of one win in six matches, a seismic victory at Celtic Park on Sunday would have the outsiders peeking back through their curtains again.

How has eight-point lead been cut?

Brendan Rodgers was Celtic boss when McInnes' side overwhelmed the Glasgow club at Tynecastle in late October.

That was the Northern Irishman's final match in charge, a shock resignation coming the following day.

Legendary Celtic boss Martin O'Neill returned as interim manager to pick up the pieces and led the team to five straight league wins, closing the gap at the top.

Coupled with that has been Hearts' stuttering league form. Since beating Celtic they have won just once - a 4-0 victory over struggling Dundee.

Celtic have not pulled up trees with some league displays but have found the results, while goals have become a recent issue for the leaders.

Hearts have failed to score in two of their past four games, netting just twice in that run, and they were made to pay for failing to put the game to bed in Wednesday's 1-1 draw with Kilmarnock.

"Hearts were always going to go through a spell where they wouldn't win games but they're not losing them and that's key," said Sportscene pundit Scott Allan.

"They are coming away from these games with a point and they all add up."

Experienced manager McInnes never got carried away in the face of the media when Hearts were seemingly threatening to make the impossible possible.

A win on Sunday wouldn't sweep him away either. Nor will he be too downbeat if it is another result that does not go his way.

He is expecting Celtic to have a "lift" from the arrival of new manager Wilfried Nancy, whose first game will be on Sunday.

This season has already shown signs that an exciting new era for Hearts - and the Scottish game - could be on the way.

However, the past month has only highlighted how challenging that ambitious journey will be.