He said: "Saracens are the in-form team. Their pack usually gets them on the front foot and they have some big ball-carrying back-rowers.
"But if we can dominate the contact areas we will compete and we will be up for the match."
Saracens thumped Leicester Tigers 49-10 in Round 10 last week and will no doubt be brimming with confidence when they travel to Sixways this weekend.
But Pennell feels his team can cause a potential upset against the Premiership's form side.
He continued: "We've had some tough games this season against the likes of Northampton and Harlequins and we expect something similar to that kind of challenge.
"They have a couple of dangerous wingers so we have to be smart with how we exit our half. Ultimately we need to take the opportunities we are creating and we can cause an upset if we get things right on the day."
Pennell was impressed with Warriors' performance despite their narrow loss to local rivals Gloucester at Kingsholm last weekend.
The full-back saw his side cause problems throughout but four Billy Twelvetrees penalties ensured the hosts claimed victory.
Pennell added: "It's never a nice feeling when you lose but there are an awful lot of positives to take from it.
"Everyone was putting their bodies on the line and we were starting to play within our structures. We looked dangerous and created opportunities.
"I believe we were the better side and we put ourselves in a position to win the game. Now we just have to keep seeking improvement and results will come. I'm confident that they will."
Seated tickets for the clash are available from £24 for adults and £5 for juniors and are available by calling 01905 459309, visiting the Warriors Box Office or clicking here.