-- End of Update --
It was said that the injury, reportedly to one of his arms, wasn't serious enough to sideline the Second City Saint.
However, it appears as though Punk is hurt enough that WWE is keeping him from wrestling at house shows.
According to F4Wonline (via wrestlinginc.com), The Best in the World appeared at a Raw house show on Friday, but only to deliver a promo:
Former WWE champion CM Punk appeared at Friday's Raw live event...with Paul Heyman, but did not compete after reportedly suffering an arm injury during a match against Kane on Monday's Raw...Punk cut a promo building his scheduled match against The Undertaker at WrestleMania 29, while also holding the urn he stole on Raw.
The report goes on to reiterate that "the injury is not believed to be serious, but was enough to prevent him from competing on Friday."
That's a little worrying.
Backstage talk may say that it's not a big deal, but the fact is Punk was hurt enough to effectively be taken off a house show.
It may not be serious enough to sideline him for any extended period of time, but CM Punk is essential to this year's WrestleMania.
With two of this year's three big 'Mania feuds leading to matches that we've already seen in the last year, many are expecting Punk vs. Undertaker to steal the show.
As we know, though, Punk is no stranger to working under 100 percent; he wrestled a classic match with John Cena on Raw a few weeks ago while battling sickness.
Sickness is one thing, but an injury, no matter how "light," can be another thing completely.
Hopefully, Punk is able to recover quickly to help ensure his match with Undertaker at the Showcase of Immortals is every bit as stellar as it can be.