Defintely, he looked injured to me. He looked like he was gripping his quad or something, which would be a bad break for sure. I don't think its anywhere near as bad as the previous 2 were, but its always a cause for concern. Whenever HHH does his spinebuster, I always cringe, because if he does even a little bit wrong, he can very well blow out his quad(like he did in december of whatever year that was, 07?) In the rumble match, HHH was spinebustering people like it was out of business, and it may have caused some strain on it.
Then I believe it was a simple elimination that HHH/HBK were doing that caused HHH to strain it further. This was the point where HHH/HBK were in the ring alone and seconds before Cena made it to the match. HHH seemed to say something to HBK, and not to long later HHH was eliminated by HBK. Then the camera never showed HHH walking back from ringside, which could further the fact that HHH may be injured. I also saw Cena being shocked by it also, as he did not expect HHH to be eliminated at this point. Of course HHH was suppose to be in the final 5, along with HBK, Edge, Cena, and Batista. These were the biggest stars in the match, and it was suppose to be these 5 in the end. But then it was not to be, it was defintely a shock to see HHH eliminated so soon. Im hoping this injury is not too severe.