Wales winger Mark Jones is a major doubt for the RBS Nations clash with England after a crunching collision in the 30-22 defeat against Italy in Rome.
Coach Steve Hansen also has concerns over lock Steve Williams, who is suffering from a sore back, while Llanelli wing Jones will take a couple of days off to assess the damage.
"It was a nasty blow, and I am now waiting on medical advice and will take the next day or two off," Jones said.
"I remember chipping the ball over a couple of Italian players, and then it became a bit cloudy after that.
"I have been very sore around the mouth and the back of my head, but I am improving daily."
Wales know that they will need to make a massive improvement to compete with England, and Jones admitted that the performance level has to rise.
"There was a lack of intensity when we had the ball, and we know as players that the performance wasn't acceptable, whether we had won or lost," he added.