Ulster collapse the maul. Leinster are going to tap and go.

Sean Reffell is pinged for a no-arms tackle on Thomas Clarkson and Sam Prendergast opts for the corner again.

The answer to that is not very long sadly. James Hume leaves the field and is replaced by Jude Postlethwaite.

A real quality replacement but a big blow for Ulster and Hume. Two key men forced off inside the opening ten minutes.

Despite Jude Postlethwaite being stripped and ready to go, James Hume is going to try to continue.

That's good news but we will see how long he can last.

Ulster win a penalty at the ruck on their own 22 to ease the pressure. However, James Hume is in some real difficulty clutching his shoulder after a hit on James Culhane.

We could gave another early Ulster exit here...

Sam Crean is on after just eight minutes in place of Angus Bell who picks up an early lower leg injury in contact and hobbles his way on to the back of the stretcher.

That may well have ramifications beyond tonight for Richie Murphy's men.

Image source, Getty Images

Good Leinster pressure force Ulster to go through three phases on their own line before Nathan Doak sets up a good box kicking position and he gets it as far as the 22.

Some concern here for Angus Bell as he is down clutching his ankle/shin area.

Leinster go through the phases off the line-out and get within five before flashing wide. However, Sam Prendergast spills in contact giving Ulster a chance to escape.

Another loose Leinster lineout but Luke McGrath scrambles back to recover. After a couple of phases, the Perpignan-bound scrum half launches a high box kick and Iain Henderson is offside after the ball goes forward off Werner Kok.

Sam Prendergast goes to touch.

Ulster steal an early line-out but Leinster win the early aerial battle and bundle Werner Kok into touch.

After a moment of applause in memory of Stormers Team Manager Chippie Solomon who tragically passed away last weekend, we are ready to go.

Leinster get us going attacking the War Memorial End with Sam Prendergast launching the first kick of the game.

The teams are out on the Affidea Stadium turf in the late evening Belfast sunshine.

This really feels like the big one that it is. Third against fourth. Here we go!

Matt Gault
BBC Sport NI senior journalist at Affidea Stadium

Was keeping an eye on Sam Prendergast during the warm-up. He looked vocal and confident as the away side ran through a few attacking drills.

It's a big night for the Leinster number 10 in just his second start since falling down the Ireland fly-half pecking order during the Six Nations.

Ulster back Zac Ward says the rivalry with Irish rivals Leinster makes tonight's game between the two teams at the Affidea Stadium "a spicy one".

Ulster sit third in the table, one point ahead of Leo Cullen's charges, before the encounter in Belfast, and aim to avenge a narrow 24-20 loss to Leinster in their previous United Rugby Championship meeting in Dublin in December.

"Any home interpro at home is a spicy one, but with Leinster I just think it goes to the next level," Ward told BBC Sport NI's Gavin Andrews.

"We know them so well and guys are competing against their opposite numbers to try and get into a green jersey as well.

"We're really looking forward to it. We don't really know what sort of team they are going to send up, but it doesn't really matter, they have a lot of talent and a lot of depth, but we're looking forward to it, to the challenge, and I really hope it stays dry."

Read more of what Zac Ward had to say in the build-up to the big game here.

Image source, Getty Images

Ulster back row Juarno Augustus says the team are focused on finishing as high up the United Rugby Championship table as they can to try and secure home advantage in the knockout stages as the battle for silverware hots up in the latter stages of the season.

Richie Murphy's side sit third in the table with four rounds of regular season fixtures remaining but face a testing run-in with tonight's visit of Leinster to Belfast followed by matches against Munster, the Stormers and table toppers Glasgow Warriors.

The South African says confidence is high after European Challenge Cup wins over Ospreys and La Rochelle set up a semi-final at home to Exeter Chiefs on 2 May.

"We are playing four of the best so all we need to do is take it week by week, recover well and then just go again when it's game day," the 28-year-old told BBC Sport NI.

"We're focusing firstly on the URC now because we want to get a home quarter-final, a home semi-final. That's what teams are playing for now.

"If we win a few games we can get second or first in the table and that's what we're aiming for."

Image source, Inpho

Ulster head coach Richie Murphy makes just one change for tonight's game.

Sean Reffell comes in to replace Nick Timoney in the only alteration from the side that beat La Rochelle in last weekend's Challenge Cup quarter-final.

There are no changes on the bench with Murphy retaining the same eight as last week in a five-three split.

In contrast, Leinster head coach Leo Cullen has made 12 changes from the side that began last week's Investec Champions Cup quarter-final win over Sale Sharks, with Ireland fly-half Sam Prendergast among those returning to the line-up.

Props Jerry Cahir and Thomas Clarkson and hooker Ronan Kelleher form a changed front row, with James Ryan captaining the side at lock.

Alex Soroka, Scott Penny and number eight James Culhane come into the back row.

Hugo Keenan starts at full-back with Robbie Henshaw coming in alongside Garry Ringrose at centre this week, while there are changes on the wings where Joshua Kenny and Jimmy O'Brien start.

In a six-two bench split, there is a place for prop Ed Byrne who returned to the province this week on a short-term loan.

Ulster: Stockdale; Kok, Z Ward, Hume, McCloskey; Murphy Doak; Bell, Stewart, O'Toole, Henderson (capt), Izuchukwu, McCann, Reffell, Augustus.

Replacements: McCormick, Crean, Wilson, Sheridan, B Ward, McKee, Flannery, Postlethwaite.

Leinster: Keenan; Kenny, Ringrose, Henshaw, J O'Brien; Prendergast, McGrath; Cahir, Kelleher, Clarkson, Deeny, Ryan (capt), Soroka, Penny, Culhane.

Replacements: G McCarthy, E Byrne, Slimani, O'Tighearnaigh, Deegan, Connors, Gunne, Frawley.

Image source, Inpho

Ulster head coach Richie Murphy says he hopes his side can exploit some perceived weaknesses they sense in Leinster's gameplan when the Irish provinces meet in tonight's crucial URC encounter.

"It's a massive test for us but we're also playing some really good rugby," Murphy told BBC Sport NI's Gavin Andrews.

"Within that Leinster system we see some weaknesses, things that we can go after, so it's going to be on the back of whether we can execute.

"We created some opportunities against them down at the Aviva and that gives us belief that on our day we can do the job."

Read more of the Ulster head coach's pre-match thoughts here.

Image source, Inpho

Good evening and welcome to our live text coverage of this evening's United Rugby Championship game between Ulster and Leinster at the Affidea Stadium.

Any fixture between these Irish interprovincial rivals requires little hyping up but with precious points at stake towards qualification for the end-of-season play-offs at stake, plus potential home advantage in those knockout stages, there is even more at stake as the season reaches its business end.

Both sides safely negotiated quarter-finals in their respective European competitions last week so confidence and momentum will be high coming into this game.

Leinster ran out narrow 24-20 winners when the sides met at the Aviva Stadium in December so Ulster will aim to turn the tables on Leo Cullen's side in Belfast tonight.

Going into the game, Ulster lie third in the URC table, one place and one point behind Leinster, so there's certainly all to play for.

We will bring you live text commentary from the game throughout the evening so you won't miss any of the action right here on the BBC Sport website. Enjoy!

Image source, Inpho