Roger Clemens faces six counts -- three of making false statements, two of perjury and one of obstruction of Congress. If convicted, he could face up to 30 years in prison and a $1.5 million fine, although 15 to 21 months is the more likely sentence under federal guidelines.
Roger Clemens, defendant
The former Yankee is among baseball's greatest pitchers, winning 354 games (ninth-best all-time) and seven Cy Young Awards during a 24-year Major League career. The former all-star also pitched for the Boston Red Sox, Toronto Blue Jays and Houston Astros during a career that continued until he was 45. He came out of retirement on three occasions, most recently midway through the 2007 season to rejoin the Yankees.
Clemens ranks third all-time with 4,672 strikeouts.
Brian McNamee, star government witness
Clemens' longtime personal trainer, a former strength coach with the Yankees and Blue Jays. A graduate of Archbishop Molloy High School and St. John's University, McNamee spent three years as a New York City police officer after college and left the force to become a bullpen catcher for the Yankees in 1993. He joined the Blue Jays in 1998, which was where he met Clemens.
Two years later, Clemens lobbied Yankee executives to hire McNamee as an assistant strength coach, even agreeing to have McNamee's salary come out of his own pay.
Andy Pettitte, star government witness
Pettitte and Clemens were once close friends and teammates who bonded over their Texas roots. Pettitte and Clemens, who both live in the greater Houston area, were teammates with the Yankees from 1999-2003 and in 2007 and with the Houston Astros from 2004-06.
Other key players
Rusty Hardin, lead defense attorney
The Houston-based Hardin has been a favorite of Texas pro athletes with legal issues, having represented Houston Rockets Hall of Famer Calvin Murphy and former Houston Oilers quarterback Warren Moon, another Hall of Fame player, among others. He's been Clemens' attorney since the release of the Mitchell Report on steroid use in professional baseball in 2007.
Dan Butler & Steve Durham, assistant U.S. attorneys
The government's lead lawyers worked together on the perjury case against major league baseball player Miguel Tejada, who in 2009 pleaded guilty to making misleading statements to Congress about performance-enhancing drug use in baseball and was sentenced to probation.
Reggie Walton, U.S. District Court judge
Walton has experience with high-profile perjury cases, having presided over the 2007 trial of I. Lewis "Scooter" Libby, chief of staff to former Vice President Dick Cheney. A jury convicted Libby of perjury, making false statements to federal investigators and obstruction of justice. Walton sentenced him to 30 months in jail.
The prosecution is expected to call as witnesses former Yankee players Chuck Knoblauch, C.J. Nitkowski and Mike Stanton, and former Met David Segui, all McNamee clients at one point. Pettitte's wife, Laura, and Yankees general manager Brian Cashman also could be called to testify.