Shirley's blogs at ESPN and elsewhere contained observations on players, teams, fans, cities, sports media, cheerleaders, the game of basketball, and topics outside the athletic sphere. He commented on topics such as the USA Patriot Act, which he condemned as "[putting] the US on a fast-track to an Orwellian destiny". His writing garnered attention from national sports media, as well as other outlets such as Newsweek, The Wall Street Journal, and the British Broadcasting Corporation.

Shirley's first book, entitled Can I Keep My Jersey?, was released on May 15, 2007 from Random House. A paperback version of the book was released on December 26, 2007.

In 2010, Shirley penned a long blog entry at FlipCollective.com about Haiti and the consequences of its earthquake. He begins the entry by stating that he has not donated to relief efforts in Haiti and "probably will not... for the same reason that I don't give money to homeless men on the street. Based on past experiences, I don’t think the guy with the sign that reads 'Need You’re Help' is going to do anything constructive with the dollar I might give him. If I use history as my guide, I don’t think the people of Haiti will do much with my money either."

Shirley added:

"I don’t mean in any way that the Haitians deserved their collective fate. And I understand that it is difficult to plan for the aftermath of an earthquake. However, it is not outside the realm of imagination to think that the citizens of a country might be able to: A) avoid putting themselves into a situation that might result in such catastrophic loss of life. And B) provide for their own aid, in the event of such a catastrophe."

Shortly thereafter, ESPN cut ties with Shirley. The company's full statement: "He was a part-time freelance contributor. The views he expressed on another site of course do not at all reflect our company's views on the Haiti relief efforts. He will no longer contribute to ESPN."

Shirley was born in Redwood City, California and grew up near the small town of Meriden, Kansas. He played high school basketball at Jefferson West High School.

Shirley worked his way from walk-on to three-year starter for the Iowa State Cyclones basketball team. He was coached first by Tim Floyd until he left the Cyclones to become the head coach of the Chicago Bulls and then by Larry Eustachy. His notable teammates included future NBA players Jamaal Tinsley and Marcus Fizer. The Cyclones progressed to the Elite 8 of the NCAA basketball tournament his junior season. In his college career, he earned three Academic All-Big 12 selections and, in his senior season, was named second-team Academic All-American.

Since graduating, the 6'10" Shirley has played power forward for thirteen different professional teams including: the NBA teams the Phoenix Suns, Atlanta Hawks, and the Chicago Bulls, as well as Panionios Athens of the Greek A1 League, Joventut Badalona, ViveMenorca, and Unicaja Málaga of the Spanish ACB League, and UNICS Kazan of the Russian Super League.

Shirley wore #45 for the Bulls and Hawks and #17 for the Suns.

He has three brothers who used to live in the Johnson County, Kansas City area, Shirley's off-season home.

He appeared in the film Glory Road (#50 for Iowa, uncredited).