Corners out: For the second consecutive day, starting cornerbacks Jabari Greer and Patrick Robinson missed practice with injuries.

Greer, who has a sore groin, was not on the field. Robinson, who hurt a shoulder in practice on Sunday, was on a stationary bike at the start of practice.

Johnny Patrick and Marquis Johnson received the majority of repetitions in their place with the first team. When the Saints used five defensive backs, Patrick shifted to nickel with rookie Corey White, a fifth-round pick from Samford, playing the other corner spot.

Injury scare: In a live tackling drill before the scrimmage, running back Mark Ingram was slow to get up and clutched his right knee after a powerful run up the middle.

Ingram, who underwent arthroscopic knee surgery in May, missed the rest of the drill but returned for the next period of practice.

A few plays after Ingram’s exit, starting guard Ben Grubbs went to the training room with an undisclosed injury. He returned about 10 minutes later and resumed practicing.

The Saints have no clear backup for Grubbs, a Pro Bowl free agent they signed to replace the departed Carl Nicks.

Hall of Fame Game approaching: The Saints are only four days away from their preseason opener against the Arizona Cardinals in the Hall of Fame Game, but the emphasis at practice remains on installation, not preparation.

“We won’t talk about Sunday until really Friday,” interim coach Joe Vitt said. “We’re still installing offensive plays, defensive plays and special team situational things. We’re still in a training camp mood. We have five preseason games. This is almost like we would treat a Black and Gold scrimmage, which we have every year.”

Addition/subtraction: The Saints announced Tuesday night they had signed defensive tackle Alex Daniels and waived cornerback Cord Parks.

Daniels, 6-foot-2 and 265 pounds, began his career as an undrafted free agent with Oakland in 2010. He was on the Dallas practice roster later that year and spent two weeks in 2011 on the practice roster of the New York Giants, playing fullback.

Parks played in two games with St. Louis in 2009, making one tackle. He was on Seattle's practice roster in 2010 and attended Minnesota’s training camp in 2011.

Follow Saints reporter Guerry Smith on twitter @CBSSportsNFLNO.