Unusual for an NFL player, Evans did not play football before high school. He attended Frankford High School in Philadelphia, Pennsylvania, where he was an All-Public League selection as a junior. However, Evans fractured his leg playing a game of pickup basketball at a church event prior to his senior year and missed the entire football season. Evans stayed focused on academics, ended up graduating 10th in his class, and with the help of his high school coach, Tom Mullineaux, was admitted to Bloomsburg University of Pennsylvania. In fact, Evans did not attend Bloomsburg on an athletic scholarship, but rather an academic scholarship.
As a junior, Evans had 88 knockdowns with 10 blocks resulting in a touchdown. In his senior season, he opened holes for fellow Little All-America selection Jamar Brittingham, who ran for 2,260 yards and 32 touchdowns. He was a finalist for the Division II Gene Upshaw Offensive Player of the Year Award in each of final two seasons.
Entering the 2006 NFL Draft, Evans was seen as a developmental prospect and was projected to move from tackle to guard in the NFL. Although he was evaluated as an early seventh round pick by Sports Illustrated, Evans was selected in the fourth round (108th overall) by the Saints, after they had traded their early fourth-round pick in the draft to the Philadelphia Eagles for veteran defensive tackle Hollis Thomas and the Eagles' mid-fourth-round pick. (The Eagles then used the pick they acquired from the Saints to draft a different guard, Max Jean-Gilles.) Evans was the first Bloomsburg player drafted since Eric Jonassen went 140th overall to the San Diego Chargers in the 1992 NFL Draft.
Evans was signed to a three-year contract by the Saints on July 25, 2006. He emerged as a consistent performer in training camp and preseason, and won the starting job after the projected starter, Jermane Mayberry, was injured in training camp and ultimately retired. In his rookie year, Evans started all 16 games, and both playoff games, at right guard. He was subsequently named to the Pro Football Weekly All-Rookie team.
In his second year, Evans started all 16 games at right guard again, and contributed to an offense that ranked No. 3 overall in the NFL. Remaining a starter in 2008, Evans was part of an offensive line that allowed just 13 sacks on the season, a Saints franchise record.
Evans was a restricted free agent after the 2009 season, and on May 5, 2010, the Saints resigned Evans to a seven-year, $56.7 million contract that was reported to make Evans the highest-paid interior offensive lineman in NFL history, surpassing Alan Faneca's five-year, $40 million deal with the New York Jets in 2008.
Evans graduated from Bloomsburg in May 2007 with a bachelor's degree in exercise science. In 2009 he established a full scholarship for out-of-state minority students enrolled in BU's Master of Science in clinical athletic training program. He is a member of the Omega Psi Phi fraternity.