First aerial test for Angus O'Brien but the Dragons captain safely diffuses the bomb.

This isn't good for Dragons though. Prop Robert Hunt has stayed down after an early tackle and is now going off on a stretcher.

On comes Cebo Dlamini - no doubt far earlier than he expected.

Off we go in Belfast!

A big one for both sides.

Chris Horsman
Former Wales prop on BBC Radio Wales

Fourth vs sixth, Cardiff has a chance to prove themselves tonight.

It’ll be a big test tonight, the pitch looks spectacular even if it is plastic!

Even with both teams being depleted, it should be a good match tonight.

Jack Walsh kicks us under way but for many home fans, the night started two hours ago.

From 5.45pm, as part of a planned protest, Ospreys supporters gathered outside the stadium with banners and placards to show support and send their own messages to the WRU.

But now, time for the actual rugby taking centre stage....

Image source, BBC Sport

Get your final predictions in ahead of both games this evening.

Andy Gray
BBC Sport NI at the Affidea Stadium

Image source, BBC Sport NI

It's been a bit of a wet and wild week in Belfast on the weather front, but thankfully things seem to have settled down a bit for tonight.

You can feel the optimism around Ulster as the supports trickle their way into the ground ahead of kick-off, but if there's one team to be wary of then it's Cardiff.

The Welsh side have pulled off two big comeback wins in their last two meetings with Ulster, although both of those were in Cardiff.

The most recent of those was in the Challenge Cup in December, when Cardiff won with a last-gasp Callum Sheedy penalty, so memories will be fresh for both sides - good and bad.

Tommy Bowe
Former Ireland and Ospreys winger

It is not just in Wales where former Ospreys have had their say this week.

Ex-Ireland winger Tommy Bowe, who spent four years with the region from 2008 to 2012, emphasised his sadness on his podcast with Donnacha O’Callaghan.

"I still have an Ospreys jersey up on the wall in my home in Ireland," said Bowe.

"Some of my greatest memories were playing with Ospreys. You just think of some of the legends that played there - Gavin Henson, James Hook, Lee Byrne, Mike Phillips, Justin Marshall - they just had an amazing squad of players and that's not even half of them.

"Great days and great memories. I just feel heartbroken for the players out there at the moment."

James Hook
Former Wales fly-half on S4C

I think it’s so important as former players to come out and support the current players, the staff and the supports.

We know first hand what it’s like and how important rugby is to this Ospreys regions.

I get told a lot ‘there’s no talent in Wales’, there is talent it just needs investment.

No one from the WRU has got in touch yet, I hope they do because we all want to work in partnership.

Image source, Huw Evans Picture Agency

This week, Ospreys head coach Mark Jones said he was "proud of how we have all stuck together" amid the off-field turmoil.

But he also warned his players that a stern test awaits against the in-form visitors tonight.

"We know the Dragons are a tough nut to crack regardless of their league position over the years gone by, particularly at Rodney Parade," said Jones.

"But what they showed last week is that they are now prepared to take that form on the road. They made life very difficult for Munster.

"I know the Dragons will be confident from that, and they'll be confident from the draw they had with us in round five. It's going to be tough."

Image source, Huw Evans Picture Agency

There was no shortage of passion when Ospreys hosted Lions last weekend, and Dragons defence coach Dale MacLeod is braced for more of the same tonight.

“There will be emotion with this game with all that is happening, but the team that plays rugby on the day will be the better," said MacLeod.

“Our boys are focussed on what we can control. It’s about going and putting a performance down and that has worked well for us this block.

“Ospreys will be tough. They are a team with a big forward pack, they general start well and are tough to beat at home."

Image source, BBC Sport/Getty Images

Leinster have just beaten Edinburgh 28-20 in Dublin, so here's a look at how things stand after that one.

With Ireland's Six Nations opener just five days away and Ulster's internationals in France preparing for it, Richie Murphy is forced into a number of changes from last week's defeat in Llanelli.

Into the front row come Rob Herring and Scott Wilson while Matt Dalton and Marcus Rea are in the back row.

In the backline, Conor McKee is at scrum half while Zac Ward returns on the wing. Ben Carson partners James Hume in the centre while Ethan McIlroy will be patrolling at full back.

The visitors also make four changes in the pack and a further five in the backline from their narrow victory over Benneton last round.

Ulster: McIlroy, Kok, Hume, Carson, Ward, Murphy, McKee, Bell, Herring, Wilson, Henderson, Irvine, Dalton, Rea, McCann

Replacements: McCormick, Crean, O'Connor, Sheridan, McLoughlin, Shanahan, Flannery, Moxham

Cardiff: Winnett, Lloyd, Millard, Emanuel, Bowen, Sheedy, Mulder, Barratt, Lloyd, Sebastian, McNally, Nott, Lawrence, Davies, Basham

Replacements: Hughes, Southworth, Cowell, Thornton, de la Rua, Davies, Evans, Halfpenny

Image source, Getty Images

Stethoscopes, scrubs and surgical masks are not the typical clothing that you would expect to see in a rugby player's kitbag but for medical student and Ulster second row Charlie Irvine, it is normal attire.

Irvine is a fourth-year medical student at Queen's University Belfast, balancing his studies with a full-time rugby career at Affidea Stadium.

The 22-year-old signed a development deal at Ulster last season to keep him at the province until at least 2027 and, when available, also captains his university rugby team.

"I have gone part-time and I am in there [university] two or three days, living as a normal student I suppose," Irvine told BBC Sport NI.

"When I am in, I am in the wards or a clinic and that is all I am thinking about. When you have tough training or a tough weekend, it helps getting out of the rugby sphere to not worry about it at all.

"It's been a whirlwind two months. [This week's] day off from rugby I think I am in a labour ward all day, it is a bit of a change of scenery from out on the pitch."

Image source, Getty Images

Cardiff fly-half Callum Sheedy kicked a last-gasp winning penalty to defeat Ulster in a Challenge Cup thriller at the Arms Park in December.

Sheedy's nerveless effort completed a remarkable Cardiff comeback from 26-12 down and ensured Leigh Halfpenny's homecoming ended in a dramatic victory.

Cardiff had raced into a 12-0 lead through tries from lock George Nott and teenage wing Tom Bowen.

Ulster rallied with tries from captain Tom Stewart, centre James Hume and a double from wing Werner Kok to give the visitors a 14-point lead after 65 minutes.

Cardiff responded with tries from replacement prop Danny Southworth and flanker Dan Thomas, before Sheedy stepped up with the final kick of the game.

Image source, BBC Sport

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Image source, Huw Evans Picture Agency

Tonga centre Fetuli Paea was excelling against Sale in October before a broken arm tainted his debut display.

Tonight, he's back for the first time since and is named among the replacements.

Fork the starting XV that came so close in Munster, head coach Filo Tiatia makes three enforced changes with second row Ben Carter and number eight Aaron Wainwright on international duty, while prop Rodrigo Martinez is out injured.

Loose-head Wyn Jones, lock Seb Davies and blind-side flanker Ryan Woodman come into the line-up while Harri Keddie shifts to number eight.

Dragons: O'Brien (capt); Richards, Inisi, Owen, Dyer; De Beer, Hope; W Jones, Coghlan, Hunt, Douglas, S Davies, Woodman, Beddall, Keddie.

Replacements: Burrows, Morris, Dlamini, Lewis-Hughes, Minto, R Williams, Paea, C Evans.

Image source, Huw Evans Picture Agency

Head coach Mark Jones is without six key players away on Six Nations duty, but has been boosted by Wales releasing prop Gareth Thomas and scrum-half Reuben Morgan-Williams back to his squad.

Thomas is named in the starting XV for his first appearance since 7 December after recovering from a calf injury.

But with centre Owen Watkin, fly-half Dan Edwards, scrum-half Kieran Hardy, hooker Dewi Lake, lock Rhys Davies and flanker Harri Deaves all missing, Jones has also acted in the loan market this week.

Just days after completing a temporary move from Leinster, number nine Cormac Foley is among the replacements.

Outside-half Jack Walsh and hooker Sam Parry, who features for the first time since New Year's Day, will share captaincy duties.

Ospreys: Hopkins; Kasende, Cokanasiga, K Williams, Giles; Walsh (co-capt), Morgan-Williams; G Thomas, Parry (co-capt), Botha, Fender, R Smith, Ratti, Moriarty, Morse.

Replacements: L Lloyd, S Thomas, Henry, De Witt, G Evans, Foley, Nagy, Houston.

Image source, Huw Evans Picture Agency

Well, they say a week is a long time in Welsh rugby. For Ospreys fans right now though, every day must feel like a rollercoaster.

Since you joined us (and Storm Ingrid) for their epic 24-24 draw with Lions last week, the off-field commotion has escalated.

A string of former greats have put their name to a joint statement, calling for the WRU to reconsider current plans. Swansea council has labelled the proposed axing of the region "cultural vandalism," while plans to redevelop St. Helen's beyond the 2026/27 season have seemingly been put on hold.

And with the Six Nations also looming, it has been easy to overlook the prospect of an enticing Welsh derby tonight.

So welcome to our live coverage from the Brewery Field, and with both teams impacted by international call-ups, let's look at the team news.

We'll also have updates from Ulster and Cardiff, with both sides having fresh memories from December's thriller in the Challenge Cup.

Thanks for joining us.