What is wrong with Albert Pujols?

Everyone that knows me knows I love Albert Pujols. He's the greatest baseball player of his generation and he plays for the St. Louis Cardinals. But what is wrong with him? Is he just in a prolonged slump? Look at these numbers through May 2nd.

.241 BA, .310 OBP, .438 SLG, .747 OPS

Compare to his career average of:

.330 BA, .424 OBP, .621 SLG, 1.045 OPS

I know in 2007, he started off the season very slowly hitting:

.250 BA, .343 OBP, .489 SLG, .832 OPS

but this is ridiculous. Is the pressure of his free agent year getting to him? If you take out the first 10 games of the season, where he was just awful, Albert Pujols is hitting:

.291 BA, .358 OBP, .500 SLG, .858 OPS

which is more reasonable. I suppose even the greatest players of all time will have slumps, look at what happened to Frank Thomas in 1998:

.265 BA, .381 OBP, .480 SLG, .861

This was after he hit:

.330 BA, .452 OBP, .600 SLG, 1.053 OPS

from 1990 to 1997.

I can only assume it's a slump, and it happens. If he wasn't hitting any home runs or getting any hits, then I suppose it'd be more concerning. But it appears even Albert Pujols can have a bit of a down year.

Update:

This blog entry (via Rob Neyer, via this post) suggests that Albert Pujols was injured and not letting on that he was injured. It's a good argument.

After 27 games without a home run (and hitting only a measly 4 doubles, seeing his slugging percentage drop from .512 to .409), Albert Pujols hit a home run on May 23. And then he hit 4 home runs between May 30th and June 4th. It's looking like that hamstring injury is all healed up.