The camp of a long time, dominant UFC champion saying that their fighter might be edging closer to retirement is nothing new. It's just that it's usually coming from those around Anderson Silva, and now it's coming from Firas Zahabi, trainer of Georges St. Pierre.
Zahabi suggested to Sherdog Radio that he doesn't know that GSP can keep it up for many more fights (transcription via ESPN):
"His training camps are not sustainable forever. His training camps are very difficult. I've done a lot of training camps. I could tell you the energy, time and money and hours spent doing a GSP training camp is ridiculous," Zahabi told Sherdog Radio.
"It's borderline insane. There's a lot of effort going into preparing him for his fights.
"Can he live this lifestyle for another four or five years? I don't know. Because it's not a balanced lifestyle. It's not a balanced lifestyle for him."
"He's going to have to make that choice one fight at a time. Does he want to go through another training camp? Right now at this time, yes, for sure. There's no doubt in my mind he wants to do another one,
"But down the line, two or three more training camps, is he still going to want to do it? That's up to him. Does he still have the fire and the passion? We'll see."
There was a certain portion of fans and media on Twitter during the Nick Diaz fight suggesting that GSP looked like he wasn't quite "in his prime" any longer. While that may or may not be true, it isn't a wild suggestion to say that there is a limit to how long guys are able and willing to put in the kind of work GSP does to be one of the best ever.