In fact, the Italians' last victory came against the Blues nearly a year ago to the day, while the last five meetings between the two sides have ended with two wins apiece and a draw.
Therefore the Welsh region's four-game GUINNESS PRO12 winning streak is far from guaranteed to turn into five come Saturday evening - and John says his side have left no stone unturned in preparation.
"It's a massive game for us," said John. "We've had a good run in the GUINNESS PRO12 and now we go to Italy and it's a huge game for us to keep momentum going.
"Treviso away has not been very successful for us the last few years. We have got to realise how hard this game is going to be and be full switched on.
"We have to go out there with the right attitude. We can't underestimate them; we can't afford to do that.
"That's been the driver for training this week - we have to perform in difficult places where we have found it difficult in the past.
"If we want to continue in the direction we are going in we have to produce. Both teams will be missing players to the internationals, but we have just got to look after ourselves and prepare as best as we can."
To buy tickets for the GUINNESS PRO12 Grand Final click here. Also follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the GUINNESS PRO12.