Most observers expect Pennant's injury to rock the club, but it may well be the opportunity Rafael Benitez needs to breathe life into his team.
There's no doubt Pennant has been a mainstay on the right side for Liverpool—but his absence isn't equivalent to that of Daniel Agger, Xabi Alonso, or Fernando Torres.
Steven Gerrard has had a very poor last few games in the centre of the park. With Pennant out, Rafa can move Gerrard to the right—which may well be what Gerrard needs to get back on track.
There's also the opportunity to give Yossi Bennayoun more time. Whilst I'm not a big Bennayoun fan (he's far too inconsistent, and gives the ball away too easily), he does bring the ability to challenge defenders and create shots for himself.
And then there's Ryan Babel.
Babel was signed as a left winger, but the majority of his playing time has come at striker, and he's right-footed. His specialty on the left is cutting inside for shots—not exactly the answer for a team in need of width.
With Pennant gone, Rafa should try Babel on the right. He certainly has the pace, and he's willing to take on defenders.
The only certainty here is that the Pennant injury won't be as critical a blow as those suffered by Agger, Alonso, and Torres. With a little luck, in fact, it may just turn out to be a blessing in disguise.