DRAGONS centre Jamie Roberts will miss the first block of fixtures in the United Rugby Championship after having knee surgery.

The 34-year-old former Wales and Lions powerhouse featured off the bench in the opening weekend loss to the Ospreys in Newport but missed Sunday's 7-6 loss to champions Leinster.

That was after he went under the knife to resolve a niggle with the Dragons making the decision to use the break for the autumn internationals to get the issue sorted.

"Jamie has had an operation that will rule him out for the next six or seven weeks," said director of rugby Dean Ryan.

"It just got to the stage where it was going from week to week and not improving, so we made a decision to go for surgery and try and maximise the window in November to get him back on his feet."

South Wales Argus: OUT: Jamie Roberts has had knee surgeryOUT: Jamie Roberts has had knee surgery

The Dragons travel to Connacht this weekend then host the Stormers and then make the short trip to Cardiff.

The URC then breaks to avoid clashes with World Rugby's Test window before Ryan's men return for a pair of Scottish encounters, hosting Edinburgh on November 27 and going north to Glasgow the following weekend.

Roberts had a superb first season with the Dragons after arriving on a one-year contract, racking up 17 appearances and earning a fresh deal.

The Dragons are likely to continue with Aneurin Owen and Jack Dixon in midfield while Adam Warren was an unused replacement against Leinster.

The stalwart featured in his first matchday 23 for a competitive fixture since suffering a groin injury at Benetton last November.

"Anerin and Jack are growing and that was a difficult Leinster pairing," said Ryan.

"They were probably frustrated with some of the platform issues that we had because it starved them of ball but this is an opportunity to really grow into that role."

The Dragons have also fielded winger Jared Rosser in midfield recently but won't yet be calling on summer signing Cory Allen.

The six-times capped Wales centre trained with the region after leaving the Ospreys at the end of the season, showing sufficient progress on his return from a serious knee injury to earn a deal.

Allen has not played since September 2019 and the Dragons are not going to rush him back into their squad.

"Let's not make timelines around Cory, let's make it a fingers crossed story," said Ryan.

"He is doing really well and it's been a long time after a horrendous injury so I don't think timelines are helpful."

The Dragons are likely to be forced into one change for Connacht after flanker Ollie Griffiths suffered a head injury against Leinster.

He will follow the return to play protocols but there is a six-day turnaround to Galway.