|Judgement Day: Blues v Ospreys; Dragons v Scarlets|
|Venue: Millennium Stadium, Cardiff Date: Saturday, 25 April|
|Kick offs: 14:30 BST and 16:45 BST Coverage: Blues v Ospreys live on Scrum V Live on BBC Two Wales, BBC Radio Wales, BBC Radio Cymru, online, mobile, the BBC Sport app and Connected TV. Dragons v Scarlets live on S4C, BBC Radio Wales, BBC Radio Cymru, online, mobile, the BBC Sport app and Connected TV. Live text commentary on both matches on BBC Sport website.|
National coach Warren Gatland has confirmed that he is returning to Wales to see Blues v Ospreys and Dragons v Scarlets at the Millennium Stadium.
Gatland has been at home in New Zealand, but will be among a crowd expected to be around 50,000 for the "Judgement Day" matches on Saturday.
Speaking in March, Gatland said regional form will play a part when he selects his squad for the World Cup.
"All the national squad coaches will be watching even more closely," he said.
The Welsh Rugby Union are staging back-to-back Welsh derbies for the third time, and expect a record attendance with more than 40,000 tickets sold.
Ospreys are trying to secure their place in the top four of the Pro12, while Scarlets are chasing automatic qualification for the European Champions' Cup.
The bulk of Wales' squad for the 2015 Six Nations will be in action on Saturday, with Gatland due to name his preliminary squad for the World Cup on 7 June.
"There is nothing like a derby match to put players under pressure to perform and with the added extra factor of being played out at the Millennium Stadium it should be a revealing day from a coach's point of view," added Gatland.
"We have a good idea of what our best team is at the moment and we have been really happy with the players in the Six Nations and particularly with the performance against Italy in that final weekend when they did everything that was asked of them.
"But there are always players that time it right and come into consideration at World Cup time when form becomes an incredibly important factor."