I don't always agree with Bill Simmons, but he wrote something good on this subject:
I hate to keep harping on Steve Nash's faults because he's such an extraordinary offensive player to watch, and he was spectacular in back-to-back Game 7s ... but when you play 35 minutes a game during the season, followed by a seven-game series against the Lakers in which you didn't have to play any defense at all, followed by a couple of tough games against the Clips, I don't want to hear how tired you are. Especially if you're a two-time MVP. The fact remains, Nash played only two good games in that series -- Games 1 and 7 -- and the Suns still won the series. If Nowitzki goes 2-for-7 against the Spurs, Dallas is going home right now. So who's more valuable? You tell me.