EAST RUTHERFORD, N.J. -- The New York Giants suddenly have added concern at defensive end.
"He's got a tight back," coach Tom Coughlin said after practice without being specific. "They're just taking the precautions."
Coughlin hopes that Tuck will be able to play in New York's preseason opener at Pittsburgh on Saturday night, but added his condition needs to improve a little.
Bothered by a number of injuries, including a neck problem, Tuck had an off-season in 2012, finishing with four sacks and 55 tackles in 55 games. As the team's defensive captain he took a lot of criticism when the Giants finished next to last in the league in defence.
Tuck was not available for comment after practice.
Backs are a touchy topic.
Jason Pierre-Paul played 16 games last season with a sore back, but never disclosed the seriousness of the injury. He had disk surgery in June and he wasn't sure on Tuesday whether he would be ready to play in New York's season opener at Dallas on Sept. 8.
Free agent signee Cullen Jenkins, who has been starting at defensive tackle, moved to the outside to take Tuck's spot at end.
"He's a tough guy to block no matter where he is," Coughlin said about Jenkins, who played last season with Philadelphia. "He's very effective, very good. Moves well. Just gives us a nice piece of versatility to be able to play him basically wherever we need."
Shaun Rogers took over at defensive tackle for Jenkins.
New York has had a couple of injuries this week that may make some players a question mark this weekend.
Justin Pugh, the offensive tackle who was the Giants' first round draft pick, running back Ryan Torain and guard James Brewer have suffered concussions this week and have missed practice. Rookie safety Cooper Taylor was out Wednesday with a hamstring injury.
The injury to Brewer has created a chance for guard Brandon Mosley, a fourth-round draft pick a year ago who spent the season on injured reserve with an ankle problem.
Brewer had been starting at right guard with veteran Chris Snee on the physically unable to perform list. Snee, who had off-season hip surgery, was activated on Tuesday but he is not ready to play in a game, so Mosley will start.
"He's had some very good practices," Coughlin said. "He occasionally suffers from a lack of experience when something new confronts him. He's been impressive. He's a tough kid. He's battling."
The Giants also announced the retirement of safety Deon Grant, who sat out last season. He last played in the Giants' Super Bowl win over the New England Patriots in February 2012.
"He's one of our guys. He did a great job when he was here. Mr. Versatility," Coughlin said. "He played linebacker. He played back in the secondary. We had a package basically designed to get him and others on the field at the same time and he responded very, very well. He was a very, very smart player; a guy who could direct traffic back there. The guys really respected him. He had the ability to recognize when things weren't championship quality and he would call people's attention to that."