After more last-minute heroics against Scarlets at Musgrave Park last weekend, Munster's Head Coach is expecting another difficult encounter against Pat Lam's side.
"It's always a difficult match, I remember vividly going to the Showgrounds last year at this time and we squeaked a win on a wet day and I suspect it will be no different on Friday," said Penney.
"If you underestimate them, they will sting you and that's another challenge this week.
"We've picked up a couple of results this year that we struggled to get last year which is great and heading into a tough game, a local derby match, the Connacht lads would like nothing better than to come here and smack over Munster."
The Westerners moved off the bottom of the PRO12 table after beating Newport Gwent Dragons on Saturday night and the Munster coaching staff are doing everything they can to ensure that the players are mentally prepared for the task.
"It's what the 15 guys on the track are thinking that's the important thing so, as a management group, we'll prepare the same," he said.
"Our detail will be as diligent as it always is and the key thing is that the players embrace that and I think they're getting a bit of confidence in knowing they can win the tight ones."
Stephen Archer starts from the bench and the prop knows that Munster will need to be on top of their game if they're to extend their good form into the new year.
"They'll be aggressive, in our faces and we'll have to be on top of our game - especially physically. If you're not physical against Connacht you might as well not turn up because they're a good side.
"They had a great result over in Toulouse which is a great achievement and it will be talked about for years."
Tickets are now on sale from the mobile ticket office at Hassett's Cross and from the West Stand ticket booth from 5.15pm.
Ticket prices: Cat A Stand €40, Cat B Stand €30, Cat B Junior Stand €10, Terrace €20, Junior Terrace €7, Family Terrace Pack €40 (2 Adults and 2 Juniors). *Junior - Under 16 years
Munster: F Jones; K Earls, J Murphy, J Downey, R O'Mahony; JJ Hanrahan, D Williams; J Cronin, N Scannell, J Ryan; D O'Callaghan, D Foley; P Butler, S Dougall, J Coughlan Capt. Replacements: D Varley, A Cotter, S Archer, B Holland, CJ Stander, G Hurley, J Holland, D Hurley.
Supporting Nominated Charities
Munster Rugby have nominated Friday night's game as this year's "Charity Match" in a bid to raise funds and awareness for our two nominated charities for season 2013/14, Mid West Spina Bifida and CUH Charity.
To support the initiative, supporters are being asked to purchase a match programme for €5 with €1 from each programme sale donated to help raise much needed funds for the charities.
At half-time, an exclusive, signed "Charity Match Munster Jersey" will be presented to representatives of each of the charities.
Mid West Spina Bifida will also be selling the bands, embossed with "Munster Rocks", on Friday night at Thomond Park and they are asking all supporters to row in and purchase a band for €2 in order to help raise much needed funds for the charity. Bands will be sold prior to, during, and after the match and sellers will be wearing red tee shirts with MUNSTER ROCKS! on the front.