An MRI examination on Monday confirmed that Gandy suffered a torn anterior cruciate ligament in his left knee during Sunday's loss to the Tennessee Titans. The injury occurred in the fourth quarter, when Gandy's knee buckled.
Gandy, 36, will undergo surgery once the swelling in the knee is reduced, and he will be placed on injured reserve. At his advanced age, and facing a lengthy rehabilitation, it is conceivable the injury might end Gandy's career.
He has one year left on his contract, at a base salary of $3.5 million for 2008. With the Falcons clearly in a rebuilding mode now, Gandy could consider retirement, or the team may elect not to bring him back for another season in 2008.
The loss of Gandy, who had started every game for the Falcons since being acquired from New Orleans in a 2006 trade for safety Bryan Scott, weakens an Atlanta offensive line that has not played well in 2007. It likely means that rookie Renardo Foster, an undrafted college free agent who filled in for Gandy after the injury on Sunday, will move into the lineup.
Foster played for Atlanta coach Bobby Petrino at the University of Louisville. He will face a tough challenge in his first regular-season start next Monday night, when the Falcons host the New York Giants and right defensive end Osi Umenyiora. With seven sacks on the year including six in a Sept. 30 victory over the Philadelphia Eagles, Umenyiora is the NFL's sack leader.
Falcons starting right tackle Todd Weiner is also playing at less than 100 percent because of a knee injury but is expected to start against the Giants.
A first-round selection of the Los Angeles Rams in the 1994 draft, and the 15th prospect chosen overall that year, Gandy has appeared in 213 games, including 206 of them as a starter. The only game Gandy had missed entering this season was in 2001.
The former Auburn star has played for the Rams (1994-98), Pittsburgh (1999-2002), New Orleans (2003-05) and Atlanta (2006-07).
Senior writer Len Pasquarelli covers the NFL for ESPN.com.