Etherington has started only two of the Potters' past seven games due to various issues that are understood to be linked to a defect in his jawline. Chief among them is a back complaint, but Stoke boss Tony Pulis revealed a few weeks ago that Etherington was to have a jaw brace made for him by a specialist to deal with the problem and the 29-year-old has now declared himself fully fit to take on the Hammers. "I have always suffered with my back, especially after games," Etherington told www.stokecityfc.com. "I suppose you put your body under so much stress during the 90 minutes that inevitably you will begin to feel the effects of that. "It has always been stiff and sore, but recently it was getting progressively worse and we didn't really know what the reasons for that were. "It was extremely worrying to be honest because it was something not too common. "But we have got to the bottom of it now. The medical team and the sports science side of the backroom staff have been brilliant, and I am absolutely delighted to have sorted it out. "We have just got to manage it correctly now." Etherington had to come off in the first half of Stoke's fifth-round victory over Brighton, but having sat out the Barclays Premier League trip to Arsenal which followed, he has appeared as a substitute in the past two fixtures - league games against West Brom and West Ham - and is feeling in good shape. "I got half an hour against West Brom which was good, but having been out for a little while it is hard to get straight back into the swing of things, especially when you haven't done much training," Etherington said. "Last week at West Ham I felt a lot better after doing a few days of training. "My sharpness is better and now, with a full week of training behind me, hopefully I can be out there all guns blazing on Sunday afternoon and try to help the club get to Wembley." Meanwhile, Pulis has confirmed that goalkeeper Thomas Sorensen will once again step in for Asmir Begovic, as in earlier rounds. "Thomas will definitely be one change that we make on Sunday," Pulis said. "He has shown what an outstanding professional he is since losing his place to Asmir and he deserves the opportunity to come in for this big occasion. "We are extremely fortunate to be as strong in the goalkeeping department as any other Premier League club with Thomas, Asmir and, of course, Carlo (Nash) as well." Begovic, who took over Sorensen's position as first-choice stopper in October, was involved in a mix-up with Marc Wilson which led to a goal for West Ham in the Potters' 3-0 defeat at Upton Park last Saturday, although Pulis stressed that had not played a part in his thinking for this weekend. "The change would have been made anyway because it is what we have done in the cup competitions so far this season. Nothing has changed," said Pulis. "Asmir is going to be a fantastic goalkeeper, but even young players with his talent are prone to making the odd mistake. That is all part of the learning process."
