Gloucester's Bortolami said: "Wales may have lost their first three games but they are going to be all the more dangerous because of the pressure they are under.
"Sometimes the fear factor can work in your favour and the best way to react to pressure is to come up with a great performance. That's my big fear against Wales; that we get caught up in the backlash of four defeats in a row. They played well against the best two teams in the Championship, Ireland and France, and they seemed to find their game again in Paris.
"Stephen Jones is a great player and we know we will have to keep a very close eye on the Welsh backs, like Shane Williams. If we don't contain the Welsh runners we are going to be in big trouble."
Bortolami also reckons the return of Gareth Thomas will fire up Wales. The former British & Irish Lions skipper missed all three RBS Six Nations games so far but is back to take a place a place on the bench on Saturday after serving his four week ban following his run-in with Ulster fans last month.
He said: "It probably sounds strange but I'm actually pleased to see that Gareth Thomas is available again for Wales, he's a great player. He has wonderful skills, has a good mindset and is a talisman for the Wales team. It might not be good for the Italian team that he is back, but it's good for the game."
Italy are on a high after claiming their first away victory in the Championship, 37-17 at Murrayfield two weeks ago, and will claim their first ever back-to-back wins if they slay the Dragons.
Bortolami said: "We proved against Scotland that we are good enough to win at this level - home or away. That was a fantastic feeling but we still have a big margin to grow as a team. We've had some great wins in the past, but we've never been able to reproduce it two weeks in a row, that must be the next step against Wales.
"The game is growing very quickly in Italy and good results mean more people want to come out and support us, but there is now an expectation from our fans and that will make this game even harder for us."