If you've caught Black Sabbath on their North American tour or any of the dates around the world over the past year or so, consider yourself lucky as it may be the final time around for the group -- at least according to bassist Geezer Butler.

While the band have enjoyed the success of their new album '13' and could be game for another disc, touring may be a whole other beast. In a new interview with the Chicago Sun-Times, Butler hints that he's enjoying the current trek for all that it's worth as he's well aware this could be their final go-around.

The bassist explains, "I've always said as long as I can play, as long as I can do it to a good level, then I'll keep doing it because I still really enjoy playing. I'll know when the day comes I can't do this anymore, can't play to my usual standards. That's when I won't go out anymore. I won't do that to me self, but at the moment, I just love playing with the band. It probably will be the last time, will probably be the last tour, but I want to go out on a high. The band is playing really well at the moment."

When asked why he feels this might be the final tour, Butler stated, "I don't know. I just got a feeling. It's getting tough, it really is. I can't lie about that. I'm old now. It really is tough going on every night. You wake up next day, all the pains you never had before. I don't want to go onstage for the sake of money. You have to have a lot of pride in yourself and I honestly think I'm coming to the end of the top of my job."

While Butler didn't address the topic of another album directly, the band members have kept the door open in previous interviews about the possibility of recording a follow-up to '13.'