A win would put the RaboDirect PRO12 side in the driving seat to qualify for the knockout stages, and Penney is challenging his troops to make it back-to-back wins.
"The win last week gave us a real opportunity to be masters of our own destiny which is where you want to be," New Zealander Penney told the Limerick Leader.
"Last weekend's result was very heartening, but Saracens will be very tough this weekend at home - they have a lot of pride.
"There are some challenges for us in the next match. We are improving and building a bit of confidence too, so there will be fireworks again."
Penney's troops currently sit fourth in the RaboDirect PRO12 standings, with six wins and four defeats from their opening ten games.
But going into the weekend's clash, Penney has a number of injury concerns with Felix Jones, Keith Earls, Simon Zebo and BJ Botha having picked up knocks at Thomond Park.
"We do have a number of bumps and bruises," added Penney. "The training has been quite low-key in a number of areas.
"We are now waiting on the expertise from the medical staff confirming players' availability."
Guinness PRO12 Munster News
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