Empty Seats in the Cathedral ?

Did anyone else notice that at the Twins/Yankees game Monday night at Yankee Stadium, that about one half of the seats were EMPTY? No rain, no blizzard and no signs of a valid reason. This just stuck me as very odd that the first week of the season and the Yankees cannot fill the place? I wonder if anyone has an idea as to what the reason may be?

Weather: 57 degrees, cloudy.
Wind: 5 mph, In from RF.
T: 2:38.
Att: 40,311.

It can't be that the Yankees are horrible, since they are the Yankees after all and they always win and draw fans. Now I am sure the 40,311 listed officially, did not all show up. There were empty seats spread out all over the ballpark.

Very odd... anybody have an explanation?