Orioles "44"

Why do the Baltimore Orioles all have a “44” on their left sleeves?

In memory of Elrod Hendricks

To memorialize Elrod Hendricks, number 44, a long time Baltimore coach who died in December.

http://www.washingtonpost.com/wp-dyn/content/article/2005/12/22/AR2005122201833.html
(on preview, what Airman said, but I’m still posting this.)