The west country club are top of Pool Two after wins over the Newport Gwent Dragons and Bordeaux-Begles, while Mogliano are rock bottom having conceded 82 points in their two defeats.
Bath have made a host of changes, with Catt and lock Dominic Day the only two players to keep their places in the starting XV from last weekend's meeting with Exeter.
But Catt insists Bath are not taking their Italian hosts lightly.
He told Bath Rugby TV: "Italian packs are normally pretty feisty so for us it is probably not going to be much of a break because we are still going to have to bash into each other. It will be as it is every day work hard and get us some go forward.
"We have not seen a lot of them, it's not a bad thing. It means we have to focus on our jobs and what we are going to do this weekend without having seen a lot of footage of them.
"It's going to be interesting and we will see what they have got to offer."
Wasps are also top of their group, and travel to French side Grenoble looking to strengthen their grip on Pool Four.
The Aviva Premiership side suffered the blow of losing England wing Christian Wade for six months with a foot injury earlier this week.
He is replaced by Josh Bassett, while lock Tom Palmer, scrum-half Joe Simpson and fly-half Joe Carlisle also come into the side.
Director of rugby Dai Young believes the back-to-back fixtures against Grenoble represent the start of a period that will define their season.
He said: "I have always highlighted the importance of this period either side of Christmas in influencing what direction your season can take and these back to back games against Grenoble could, to a great extent, determine the success of our European campaign.
"Winning in France is always a tough task and Grenoble have proved in their domestic league how dangerous they can be so we are under no illusions that this will be a real test for us this weekend.'
Elsewhere, French club Brive travel to face Bucuresti in Romania in Pool Three, while in Pool Five Cavalieri Prato host Lusitanos.