The Azzurri may have slipped to a 28-17 defeat at the hands of the Triple Crown holders, but only after they had given their much vaunted pack a real grilling and gone close to causing a major upset.
Ruddock knows that Wales were on the wrong end of a 30-22 defeat the last time they played in Rome, so he is taking nothing for granted as he tries to steer Wales to a second successive victory at the start of a championship campaign since 1994.
"I firmly believe Italy are the most improved team in world rugby. They took a real step forward from the Autumn Internationals both in their forward play and behind the scrum and they pose a threat all over the field," said Ruddock.
"I had a smile on my face last Sunday morning after our win over England, but it had gone by the afternoon because Italy impressed me so much against Ireland. We have to believe in ourselves after the win over England and I think we have made big strides.
"We have encouraged the players to be more vocal and there is more leadership in the side. We are confident about where we are as a team and we know we didn't play as well as we can do last week. That means we are hungry for a better performance and for another win over a team that is bound to provide tough opposition.
"Italy caused many problems for Ireland last week, especially around the half-backs. I've told the players we need to seize control early in the game rather than let them dictate to us. They harassed the Irish and played some great rugby. If their winger hadn't dropped the ball over the line they could have won.
"We have to believe in ourselves. We have taken on the might of the English pack, now we have to step up and improve again. The aim is concentrate on our mind-set and our game, and not worry too much about Italy. There are two teams in this game and they will have to worry about us too."
Italian Coach John Kirwan said he had no thoughts of revenge following his side's defeat by Wales in the 2003 Rugby World Cup, but is looking for another victory on home soil.
"We will have to show everything we have got if we are to win again. Our first challenge is to produce the same mental attitude as we showed against Ireland last week," said Kirwan. "The second is to make the right decisions at critical moments during the game. Then the real icing on the cake would be to win."