Nathaniel Clyne left the field against the Blues last Saturday and required stitches on a deep laceration to the ankle, but fortunately there was no damage to the major structures.
Vieira said: "Nathaniel went to the hospital and is back at home now. He came in for training once every two days to do some work with the physios but it’ll be a couple of weeks until he’s back on the field."
Turning his attention to the wider match, Vieira said: "It’s going to be a challenging game. We know how good they can be and how well they can play. At the same time we’re at home and I’ve been pleased with the way we’ve played the last couple of games, even if we didn’t get the results we deserved.
"We need to improve some parts to allow us to win football matches.
"We have to be at our best. We have to take our chances. We have to be more clinical in both areas of the field. And [we have to] play the way we know we can."
