The SPFL campaign rolls on into the fourth round of fixtures this weekend.

Already the runners and riders in each league's respective title fights are becoming clear as are indications as to which sides face an arduous campaign ahead.

Here we look at the key talking points - the early pressure on Rangers, Celtic's Saints challenge, Jon Daly's job prospects, a telling fixture in the Championship and Ayr's remarkable goalscoring exploits.

Rangers travel to Dingwall this Sunday with Pedro Caixinha already under pressure after consecutive draws saw his side fall five points off the pace after just three games.

Following last weekend's stalemate with Hearts at Ibrox boos were audible from the home support.

The Portuguese boss is relaxed about any criticism of his side's stuttering start, however, insisting that "when the dogs bark, the caravan keeps moving".

Rangers' moment is spluttering at the moment though, and Caixinha has to find top gear soon before Celtic disappear from sight.

In Jim McIntyre's Staggies they face a side who had their number last season, with Rangers held to three draws in three league fixtures with the Highlanders.

County captain Andrew Davies believes County will find confidence from their results last time out.

He said: "We did well against them last season and hopefully we can do that again.

"I think they are stronger than last season, but we know that if we can get in the faces of teams coming here then we are going to make it difficult which I am sure we will do on Sunday."

Celtic extended their domestic unbeaten run to 52 matches against Kilmarnock last weekend, 48 of which have ended with the Parkhead side taking all three points.

This weekend they meet the last team to beat them in the SPFL when St Johnstone travel to Glasgow.

Tommy Wright's Saints won 2-1 on the penultimate day of the 2015/16 campaign as Ronny Deila's reign approached its conclusion.

The Perth outfit have started this campaign in fine form having won their first three top-flight matches for the first time in their history, with Rangers loanee Michael O'Halloran finding the net in all three games.

It will take an almighty effort to upset odds once again and shock Brendan Rodgers' champions on Saturday.

With the Hearts board set to announce a permanent successor to Ian Cathro next week, interim manager Jon Daly has the opportunity to further strengthen his hand.

The Irishman has steadied the ship at Tynecastle since replacing the embattled Cathro, following up a win over Kilmarnock with a battling point at Ibrox last time out.

He believes he is now ready to lead the club on a full-time basis and has urged the board to follow the structure of appointing from within after their success under Robbie Neilson.

He said: "Robbie Neilson was a rookie manager and did really well.

"From my point of view, the structure they have used before has worked and I don't see why it wouldn't work again."

STV revealed he ranks highly on the club's shortlist earlier this week.

A win on Saturday would do his chances of securing the job no harm at all.

Dundee United face the toughest challenge of their title credentials so far when they take on Jack Ross' St Mirren.

The Buddies are currently the bookies' second favourites for promotion following last weekend's 3-1 win against Livingston at Almondvale - a result that was all the more impressive after being thrashed in week two by Greenock Morton.

Ray McKinnon's United side look a tough nut to crack however, having only conceded one goal so far, and will be looking to stamp their authority over their Scottish Championship promotion rivals.

Ayr have won eight of their nine matches in all competitions this campaign, with their only aberration coming in a 5-0 thumping off Hibernian in the League Cup.

Last Saturday's win 4-3 win over Stranraer was the fourth time this season that Ian McCall's side have scored four or more goals.

They have already struck 32 times in all competitions, with Craig Moore finding the net on nine of those occasions

Arbroath are their opponents this weekend. The Red Lichties will have to find a way to shore up defensively having shipped three last time out, or face a long afternoon at Somerset Park.