"They've stung us a couple of times," said Penney. "The last two years when we were playing them at home they've been really robust and difficult to combat and I'm sure they'll have their Italian internationals hanging around.
"They'll be hurting after their Six Nations campaign and they'll want to prove some points themselves so it's going to be very challenging on Saturday night in Thomond Park," added the New Zealander.
Munster had four players sin-binned in the 29-19 defeat in Italy back in September and full-back Felix Jones is certainly not underestimating Saturday's visitors ahead of a vital series of games.
"We're not taking anything for granted this weekend," said Jones.
"It's a massive three weeks for the club, it's going to be a huge squad effort. Leinster are top so there's a massive points race on to get a spot in the semi-final and to get a home semi-final as well."
Keith Earls and Niall Scannell returned to training from injury last week and with Damien Varley also fully recovered from a delayed concussion, Penney has a large pool of fit players to choose from on Saturday.
"He's [Varley] bounced back strongly in the last few weeks which is a great thing.
"I'm always happy when an injured player comes back because it gives me more scope for selection. The medics have done a great job and a few people have taken a bit longer than expected but all in all we're heading into this block in pretty good shape."
With a trip to Leinster and a Heineken Cup quarter-final at Thomond Park against Toulouse following the Treviso clash, Penney is looking forward to tackling the business end of the season.
"It's an amazing six or eight weeks now. It's the culmination of all the work that's been put together in the last six or seven months. There will be only two teams in a position to contest a final and there's a lot of water to go under the bridge yet.
"We're desperately keen to be one of those teams in the competitions but there's a lot of work to be done yet," he added.
Munster face Treviso at Thomond Park on Saturday at 7:15pm with tickets available here.