So far reports in the local papers are that Mauer's knee is responding well in the early going. I'll be holding my breath until opening day, if not longer.
The sample size from Mauer's 2004 season is admittedly much too small to be of great worth. But that doesn't mean the power he flashed wasn't for real either. He is a very big kid with a great eye, amazing athleticism, and tremendous plate discipline. I think a case can be made that his lack of power in the minor leagues had a great deal to do with his body still developing. He wasn't 21 until after opening day last season. Not too many kids are anywhere near their physical peak at 18, 19, and 20 years of age.
I would think there were many that would have thought six homeruns would be an accurate full-season total for Mauer going into last season. I constantly hear contact hitter, which seems a bit limited. Just because a guy hits for average doesn't mean he won't hit for power (nor does it mean he will).