Exactly what happened to Pau Gasol this season?

He lost his aggressiveness in the playoffs...it didn't matter so much in the first round for the playoffs because he didn't need to be an X factor to win that series...but in the semifinals against the Mavericks we needed him to step up and try to contain an unstoppable Dirk but he played soft and let Dirk get easy shots...I guess it may be something off the court or he just wasn't hungry for a title this year !!!