Wales centre Jamie Roberts is "touch and go" for the Six Nations match with Italy in Cardiff, according to skills coach Neil Jenkins. The 25-year-old was forced off at half-time during last weekend's thrilling 19-12 victory away to England at Twickenham with a knee injury and his replacement, Scott Williams, scored the only try of the match to seal a Triple Crown triumph for the visitors. Roberts had only returned just before the start of the tournament following six weeks out with an injury to the same knee. Now there are concerns the powerful midfielder may not only miss the Italy match but a possible Grand Slam decider against France at the Millennium Stadium the following week. "With Jamie, we are waiting to find out," Jenkins said Wednesday. "He is probably going to be touch and go for the next couple of weeks before the Italy game, but he he is progressing well, his rehab is going well so fingers crossed he could well make that game." Wales are eyeing a third Grand Slam in seven years with their final fixture against France, currently also unbeaten in this season's Six Nations, looking like a winner-takes-all clash. But before Wales play France, the team that beat them in a dramatic World Cup semi-final, they face an Italy side who've shown some signs of progress despite losing all three of their Six Nations matches so far this term against France, England and Ireland. "We have a very tough game coming up against Italy and we will not be looking past that," said Jenkins. "Italy will play a tough physical game. "They caused Ireland problems for 40 minutes on the weekend (before losing 42-10), they should have beaten England at home, and they had chances to win games at home last year so we know we are in for a tough afternoon." Meanwhile Jenkins welcomed Wales centre Jonathan Davies's decision to sign a new two-year contract with the Scarlets. It was a move that bucked the recent trend of leading Welsh players leaving to play club rugby in France, with James Hook, Mike Phillips and Lee Byrne all with Top 14 teams. But Davies stayed put and Jenkins said: "It is key to keep our best players playing in Wales and it's good to see him sign for the Scarlets again. "Warren Gatland (the Wales coach) has always said he wants our best guys playing in Wales if possible and that's no different now if, but it's not an easy one to get around when players decide to play elsewhere. "I don't blame them as they have a living to make and careers to keep pursuing and if they go across the water to France we have to back them in that, but obviously we want the best players playing in Wales and staying here as long as possible."