The Titans drafted him in the fourth round in 2003, and he started five of 39 games through his first three seasons with 9½ career sacks and 99 career tackles. He missed the 2006 season with a torn Achilles' tendon, then was placed on injured reserve for 2007 with a knee injury before being waived.
Long co-starred in Going Native with his brother Devan Long. The pair subject themselves to the 9,000-year-old rites of passage of the Tatooya tribe in the Colombian Amazon to begin their journey into manhood, including ceremonial vomiting, blowdart hunting and ritual whipping. The show first aired on June 7, 2015.
Long is of one-fourth Armenian descent and cherishes his heritage greatly. He has a tattoo of the seventh letter of the Armenian alphabet (Է) over the Armenian flag on his biceps. Rien Long's trip to Armenia and Nagorno-Karabakh in March 2006 was the subject of a feature-length documentary, "The Long Journey from the NFL to Armenia" (www.globalistfilms.com).
Just before midnight on January 21, 2008, Long crashed his 2005 Ford Mustang into a rock wall while driving too fast on an I-40 on-ramp near downtown Nashville. Long was taken to Vanderbilt University Medical Center where he suffered injuries that left him in critical condition.