Wasps face starting their defence of the Heineken Cup without their England scrum-half Matt Dawson, who could be out of action for three weeks after straining a hamstring against Newcastle on Sunday.

Dawson, dropped from the national squad last month, will be sidelined for at least a fortnight, adding to Wasps' already chronic injury problems. He was signed to provide cover for Robert Howley, who will be out until January at the earliest with a wrist injury, while the 18-year-old scrum-half Warren Fury is ruled out with a cracked sternum. Peter Richards will move from the centre to scrum-half for Saturday's Premiership match at Bath, the first time the two sides have met since last May's grand final, with Dawson struggling to make the European opener against Biarritz the following weekend.

The champions Wasps have put together a four-match winning run in the league despite being without established players such as Craig Dowd, Simon Shaw, Howley, Stuart Abbott, Josh Lewsey and Fraser Waters.

England's problems in the back row will not tempt Neil Back to come out of international retirement. "There is no going back," said the Leicester flanker. "If club games were not staged on international weekends it might be different but Leicester have given me tremendous support over the years and it is time to pay them back. Anyway, recalling me would not take England forward."

Wales called up the Gloucester forward Gary Powell for their two-day training camp this week after the national coach Mike Ruddock watched the prop against Harlequins last Saturday. "Gary is certainly worth a look at," said Ruddock. "We invited Warren Fury to train with us earlier in the season because he is from Swansea and has been involved with the England Under-19s."

Wales kick off the November series of internationals against South Africa next month with Ruddock looking for a return to the style that earned them plaudits at the end of the World Cup last year. "We have lost Iestyn Harris in the centre and need a second passer in the midfield to allow us to use our pace," he said. "Gavin Henson is certainly an option there."

Ruddock's assistant Scott Johnson said his aim was to provide four Welsh backs to the Lions' 22 for the first Test against New Zealand next June.