Hearts, Rangers, Celtic - who will lead Premiership by end of Sunday?

Hearts head coach Derek McInnes has labelled Sunday's meeting with Edinburgh rivals Hibernian as their toughest test.

That might raise a few eyebrows, but you can see why. Hibs dismantled Hearts for 50 minutes at Easter Road in December, storming into a 3-0 lead.

Hearts scored twice and were pressing for an equaliser by the end, but it was one of their most bruising experiences this season as they seek a first title since 1960.

Hibs, who are chasing European football for the second straight season, have their own motivations as well as the derby bragging rights and the glee of derailing their rivals' title tilt.

Hearts' away form is also a concern. They have picked up just one point from their last four away from Tynecastle - at bottom side Livingston - which is why Rangers and Celtic have edged closer.

Given three of their final five games are on the road, that needs to improve.

Plus, if the Old Firm win, Hearts will find themselves two points behind Rangers and level with Celtic at kick-off, which will present its own psychological challenge.

When all that is considered, it is easy to see why McInnes thinks it could be his team's biggest test.

However, if they win it, the momentum boost could be huge.