THREE Newport Gwent Dragons youngsters have been named in Wales' squad for June's World Rugby U20 Championship but the Six Nations champions have been dealt a blow with the absence of star centre Owen Watkin.

The 19-year-old has enjoyed a breakthrough season at the Liberty Stadium, making 12 regional appearance to catch the eye of senior national boss Warren Gatland.

But Watkin, who was a leading figure in the Grand Slam, was a high-profile absentee when Jason Strange named his squad for the U20 Championship in Manchester.

The 28-strong group includes three Newport Gwent Dragons youngsters – back row Harri Keddie, tighthead prop Leon Brown and winger George Gasson – but the centre from Bryncethin will have a summer of rest ahead of a first full season as a professional.

It's a blow to Wales' tournament hopes but head coach Strange is happy to put his long-term development first.

"There has been a lot of discussion around Owen in the last couple of weeks and it's a joint decision by the Welsh Rugby Union and the Ospreys," he said.

"It's the best for Owen to go through rehab and a really good pre-season under his belt. Our main objective is ultimately to as many of these players through this (U20) World Cup and be successful but to try and get the players through to 2019 and 2023.

"I'm obviously disappointed but the bigger picture is all about what's best for Owen's development and what's now important is that we work with Kieran Williams, who is coming in, and the other centres extremely hard to get the best out of those players.

"There's no need for an operation but it's just managing Owen's workload. He has had issues with his knee over the last couple of months and just needs to make sure he is in a good place when he hits next season."

Watkin expressed his disappointment but knows the importance of starting pre-season at 100 per cent.

"In the long run it's best if I don't go and develop myself here because hopefully this is where I am going to be for the rest of my career," he said.

"I am going to support them as much as I can because I want them to do well. I will try to get and watch the match against New Zealand. I will see if I have time.

"It will be hard and I have to get on with things and make sure I do what is best with me in the future.

"Steve (Tandy, Ospreys coach) was pretty clear with me that he didn't want me to go from the start because he wants me to develop here.

"They asked me what I wanted to do and I said I wanted to go because of the opportunity but I also said I wanted to stay because I wanted to get my knee better and progress with the Ospreys.

"I have patella tendonitis. It is quite sore but hopefully I can get over it and be fit for pre-season."

Wales have a tough group in Manchester that pits them against Ireland, Georgia and then New Zealand.

Preparations for the tournament will include a training camp in Monmouth while Dragons lock Bryce Morgan, centre Connor Edwards and wing Jared Rosser are part of the extended squad.

Forwards: Tom Phillips (captain, Scarlets), Rhys Fawcett (Scarlets), Corey Domachowski (Blues), Leon Brown (Dragons), Kieron Assiratti (Blues), Dillon Lewis (Blues), Liam Belcher (Blues), Dafydd Hughes (Scarlets), Adam Beard (Ospreys), Seb Davies (Blues), Shane Lewis-Hughes (Blues), Shaun Evans (Scarlets), Harrison Keddie (Dragons), Morgan Sieniawski (Blues), Josh Macleod (Scarlets)

Backs: Reuben Morgan-Williams (Ospreys), Declan Smith (Scarlets), Daniel Jones (Scarlets), Billy McBryde (Scarlets), Jarrod Evans (Blues), Kieran Williams (Ospreys), Joe Thomas (Ospreys), Harri Millard (Blues), Tom Williams (Ospreys), George Gasson (Dragons), Keelan Giles (Ospreys), Rhun Williams (RGC 1404), Joe Gage (Ospreys)

Wales' fixtures: Ireland – June 7 (5.30pm); Georgia – June 11 (3.45pm); New Zealand – June 15 (5.30pm).