Worcester v Doncaster: Dean Ryan makes 11 changes

Dean Ryan's Worcester now have an 11-match winning run at Sixways stretching back to last April

Worcester Warriors director of rugby Dean Ryan reverts to a near full-strength side as he bids for a 19th straight win in the home meeting with Championship strugglers Doncaster.

Ryan rested almost his entire first XV for last week's 24-10 British & Irish Cup quarter-final win over Pontypridd.

He remains without star full-back Chris Pennell, who has been picked for England Saxons duty in Ireland.

But he makes 11 changes for the return game with Clive Griffiths's Doncaster.

Jonathan Thomas, who signed a new two-year contract, moves to lock forward to accommodate skipper GJ van Velze in the back row.

Among the replacements is loose-head prop George Porter, who could make his first Warriors appearance of the season after returning from loan at Nottingham.

As well as Pennell, Richard de Carpentier and James Stephenson are both missing, having been named in the England Sevens squad for the Wellington leg of the Sevens World Series.

Doncaster coach Griffiths, who was assistant to Mike Ruddock at Worcester for two years from 2007 to 2009, makes just three changes from the side that comprehensively overcame Munster 'A' to join Worcester in the last four of the British & Irish Cup.

The semi-final draw is scheduled to be made on Monday, 2 February.

Meanwhile, Worcester forward Andries Pretorius has retired on medical grounds after being diagnosed with a rare autoimmune disorder.

The 29-year-old, who won two caps for Wales, joined the Warriors from Cardiff Blues last summer but did not make an appearances for the club after suffering calf tears in pre-season training.

He has now been diagnosed with Neuromyotonia, or Isaacs' Syndrome, a disorder which causes muscles to continuously cramp, preventing them from recovering after exercise.

Worcester Warriors director of rugby Dean Ryan:

"Doncaster have improved a lot since we last met them, although their league position doesn't necessarily reflect that. They comprehensively beat a good Munster A side in the B&I Cup last weekend so we know they'll be a stern test.

"They're a very big side. The pace of the game is crucial to make sure we don't get sucked in. We've been getting good starts recently but sometimes you have to adapt to what's happening.

"We've now got 22-23 players that we're mixing around into that starting XV. The net isn't as wide now. It doesn't mean we'll keep using the same XV, but you can start to get an idea of the people that are in contention."

Warriors: Howard; Hammond, Stelling, Symons, Biggs; Lamb, Arr; Bower, Creevy, Schonert; Williams, Thomas; Senatore, Betty, van Velze (capt).

Replacements: George, Porter, Daniels, Sanderson, Mulchrone, Mieres, Grove.

Doncaster: Jarvis; Flockhart, Bulumakau, Armitage, Lewis; Francis, Maplesden; List, Hunter, Quigley, Hotson, Phelan, Challinor, Hills (capt), Shaw.

Replacements: Bergmanas, Veikoso, Davies, Eggleshaw, Clark, Fosita, Hoadley.