England are continuing to monitor the fitness of Brad Shields as they step up preparations for their Guinness Six Nations opener against Ireland in Dublin.
Shields has been unable to train with team-mates so far at the pre-tournament camp in Portugal as he continues to rehabilitate a side strain that prevented him from playing for Wasps last weekend.
"Brad is continuing his recovery, doing some good running sessions and is increasing that day on day," forwards coach Steve Borthwick said.
"He hasn't been in team training yet but we're aiming for him to be in full training next week."
Shields has been earmarked to start the Aviva Stadium showdown with Joe Schmidt's champions at blindside flanker, while rival Chris Robshaw makes his comeback from knee surgery for Harlequins this weekend.
If the New Zealand-born back row fails to recover in time, England have a host of options as cover, including Mark Wilson and Jack Clifford and versatile locks Maro Itoje and Courtney Lawes.
"Mark Wilson in particular has shown how he can play across all back-row positions," Borthwick said.
"His performances in the autumn playing at eight were outstanding. He'll have played more at flanker than he has at eight, so that's one option. Jack Clifford is another option and he can play for us across the back row.
"And then we have the versatility of a couple of our second rows to play in the back row."
Captain and fly-half Owen Farrell is winning his race to be ready to face Ireland after undergoing surgery to repair a damaged thumb tendon.
"Owen has been training with the team, doing non-contact to allow the wound to heal," said Borthwick, who also revealed that Fiji-born wing Joe Cokanasiga is on course to recover from a knee issue.
"Everything's on track and there's no issue. He's passing the ball. We anticipate he'll be in full training next week. That's the plan."