Schlereth was selected in the 10th round (#263 overall) of the 1989 NFL Draft by the Washington Redskins. He played 12 NFL seasons—six with Washington (1989–1994) and six with the Denver Broncos (1995–2000). He was a member of three Super Bowl championship teams (one with the Redskins and two with the Broncos) and was selected to the Pro Bowl for his performances in the 1991 and 1998 seasons.
Before ending his playing career, Schlereth endured 29 surgeries. Twenty of those surgeries were performed on his knees (15 left, five right). After the 13th procedure on his left knee on July 24, 2000, Denver Broncos head coach Mike Shanahan stated, "He has a great pain threshold. I think the doctors said that it was the worst knee that they've ever seen." Schlereth would have two more procedures on his left knee during the 2000 season, his last in the NFL. His injuries are documented on Athlete 360, the new sports medicine television show hosted by Schlereth's former Redskins teammate, Dr. Mark Adickes.
On April 18, 2001, Schlereth announced his retirement. "The reason I came out here today was to announce that I have just signed a six-year, $42 million contract to extend my career with the Denver Broncos. The truth of the matter is, after going through my 15th operation on my left knee last November, it became painfully obvious that I couldn't sign a six-year contract for $42 worth of Tupperware. I started to realize in the last three months of free agency that there is not a lot of market for a 6'3", 245-pound guard that is 35 years old and beat to a pulp." He landed a job with ESPN soon after.
After retirement, Schlereth hosted an afternoon sports talk radio show on Denver AM radio 760 The Zone with fellow former Broncos lineman David "Doc" Diaz-Infante. The show was frequently referred to as the "Stink and Doc" show. Schlereth was a part-time analyst with ESPN for a time, commuting from Denver to Connecticut, before leaving 760 to go full-time with ESPN in 2004. Besides regularly hosting NFL Live, Schlereth is a frequent guest and fill-in host for Mike Golic on Mike and Mike in the Morning, as well as an analyst on NFL Live and SportsCenter. He has also filled in for Jim Rome on Jim Rome is Burning.
Schlereth revealed on the Mike and Mike in the Morning show that he was considering a career in acting, mainly on soap operas, under the name Roc Hoover. Schlereth originally chose the name Rock Hoover, however after cybersquatters took several domain names pertaining to that name he dropped the k from Rock and became Roc Hoover. He announced on May 4, 2007, that he was cast as Detective Roc Hoover, a recurring role, on the soap opera, Guiding Light.
Schlereth is also a featured athlete on Athlete 360, a new sports medicine television show. Schlereth formerly co-hosted a radio show in Denver on 104.3FM the Fan with former Broncos teammate Alfred Williams.
After the 2011 NFC Championship Game, Schlereth was one of the critics of Chicago Bears quarterback Jay Cutler, writing "As a guy who had 20 knee surgeries you'd have to drag me out on a stretcher to leave a championship game!"
In 2012 Schlereth appeared on the Discovery Channel show American Guns. He worked with the staff at Gunsmoke gun shop to find a suitable firearm he could use on a hunting trip with his son.