The Dragons have suffered a double injury blow to Harrison Keddie and Aaron Jarvis on the eve of the new season.

Both forwards have been ruled out until at least October, having undergone surgery for identical injuries to their bicep muscles picked up in training.

The absence of both players from the opening weeks of the Guinness Pro14 campaign – and most likely the opening weeks of European competition – will be a significant blow to Dragons head coach Bernard Jackman.

It will also bring an unwanted reminder of last season’s struggles which were prompted by a spate of injuries exposing a lack of strength in depth at the squad.

Former Wales prop Jarvis joined the Dragons this summer to try and address those weaknesses, whilst Wales U20 star Keddie is seen as one of the rising young stars of the Welsh game.

Jarvis signed for the Dragons on a two-year deal from French club Clermont Auvergne back in April.

The 31-year-old former Ospreys forward has won 18 Test caps, with his last Wales appearance being against New Zealand in 2016.

He has been reunited with ex-Ospreys colleagues Richard Hibbard and Ryan Bevington, who will also be Dragons players this season.

The fresh injuries come in the same week as former Dragons back row forward Robson Blake announced he was retiring on medical advice after concussion problems.

Blake – who was released by the Dragons at the end of last season – suffered a head injury playing for the Dragons in January.

He said: “Not the news I wanted to share, but following a long six months off with concussion I’ve been advised by medical professionals to retire from rugby.

“Thanks to Dragons for the opportunity to play professionally, and for their continued support.

“Thanks also to Bedlinog RFC and Bedwas RFC for all the happy memories of playing club rugby.

“And finally thank you to my amazing wife for putting up with me during the dark days.

“And so on to the next challenge…”