METAIRIE, La. — New Orleans Saints cornerback Mike McKenzie's fractured right kneecap will keep him out for the rest of the season.

Saints head coach Sean Payton said Monday that McKenzie will have surgery this week and be placed on injured reserve.

Coming back from a right knee ligament tear late in 2007, McKenzie sat out the Saints' first two games of the regular season, but played in the past seven and started six.

He had an interception and was credited with 22 tackles and three passes defended before his latest injury occurred during a 34-20 loss in Atlanta on Sunday.

The Saints have now lost two starting cornerbacks this season. Rookie Tracy Porter was placed on injured reserve after dislocating his wrist during a Week 5 loss to Minnesota.

Meanwhile, reserve cornerback Aaron Glenn reaggravated a left ankle injury in Atlanta. Payton said it was not yet clear how long Glenn might be out, but noted that the only three healthy cornerbacks on the roster were Randall Gay, Jason David and Usama Young.

Payton said he and general manager Mickey Loomis have begun to discuss the possibility of adding an available free agent cornerback to the active roster this week.

"Most likely, we're going to have to look at finding at least one," Payton said. "I just finished visiting with Mickey. We'll go through and identify what direction we're going with someone outside the building."