Justin Tuck, Shaun O'Hara battle injury

EAST RUTHERFORD, N.J. -- Two key Giants have injury concerns heading into Sunday's home game against Tennessee.

Defensive end Justin Tuck missed Friday's practice with a stiff left shoulder, the same shoulder that was surgically-repaired in the offseason. Also, center Shaun O'Hara is listed as doubtful after he missed his third consecutive practice with left ankle and left Achilles injuries.

Tuck said Friday that he woke up with stiffness in the shoulder but that he's confident that he'll play on Sunday.

"I woke up stiff, and coach said, 'We know what you can do and you know the offense, so sit out,'" Tuck said. "I am going to play [Sunday]."

Tuck sat out a few plays during last Sunday night's loss to the Colts with shoulder pain and acknowledged on Friday that the pain was in the same left shoulder that bothered him for most of last season.

The sixth-year pro suffered a partially-torn labrum in Week 2 against the Cowboys last season and played the entire year in pain, with the ailment protected by a harness. He had offseason surgery to correct the injury and said on Friday that he still feels in pain in that area "every day."

Tuck didn't think he'd have to play through the same pain that he endured through the final 14 weeks of 2009.

"It's different. Last year, I was injured. This year, it's just hurting, so I'm good," he said.

Mathias Kiwanuka would likely replace Tuck at defensive end against the Titans. The Giants, of course, would be losing a lot if Tuck isn't able to suit up on Sunday. Tuck managed just six sacks last season while playing through pain but had 12 in 2008 and 10 in 2007.

Giants coach Tom Coughlin didn't entirely rule O'Hara out for Sunday but lineman Adam Koets said on Friday he was preparing to start at center. Koets took snaps at center on Thursday and Friday.

"Obviously to get this opportunity, I'm excited," said Koets, a fourth-year pro drafted by the Giants in 2007. "I've been here a long time and I'm ready to show what I can do."

O'Hara initially had swelling in his ankle and then developed an Achillies injury in the preseason. He wore a boot this week to protect the ailment. He said earlier this season that he would monitor the injury throughout the season. O'Hara was not available for comment on Friday.

Coughlin said O'Hara's status wouldn't affect the Giants' approach on offense.

"This is what we've prepared for and Koets has played in there before," the Giants coach said Friday. "He's played in there with big people on his nose and done a good job."

The Giants should have a healthy Kevin Boss back on Sunday. The Giants tight end missed the team's Week 2 loss at Indianapolis with concussion symptoms. He suffered the concussion in the first quarter of the Giants' season-opening win over Carolina, when he took a helmet-to-helmet hit from Carolina safety Sherrod Martin. Boss says he's ready to play. The team listed him as probable.

Ian Begley is a regular contributor to ESPNNewYork.com.