Giants weakside linebacker Keith Rivers sat out of Sunday’s practice because of a sore hamstring, but that doesn’t necessarily mean he’s having a relapse of his injury woes.

Rivers told that his surgically repaired right wrist is doing well. The issue is that he’s been off the field for over a season, and the rest of his body is still getting acclimated to playing football again.

“Your body gets beat up a little bit easier because you haven’t been in -- just nicks,” he said Saturday. “But, as far as major things, I feel great.”

Rivers hasn’t really been practicing with the first-teamers, although that’s not necessarily a bad thing. The Giants linebacking core might be a more fluid situation this season, with Rivers and Jacquian Williams subbing in for starters Mathias Kiwanuka, Chase Blackburn and Michael Boley.

Williams and Boley are natural weakside linebackers, so the 26-year-old Rivers has put an emphasis on learning “a few positions” in multiple packages. Rivers has never officially been a strongside linebacker, but defensive shifts and sub packages have given him some familiarity with the position.

“In most defenses the strongside and the weakside are pretty interchangeable,” Rivers said. “At some point, even if you only play one side, you’re going to play on the opposite side because of motion. It’s just a matter of just feeling comfortable doing it.”

So far, so good.

Rivers says he’s comfortable with the pieces of the defense that have been installed from the OTAs until now. The challenge is to play with a natural understanding of the schemes rather than a forced recollection. Perhaps the biggest obstacle for Rivers -- who recorded 186 tackles for the Cincinnati Bengals in three years before being traded to the Giants -- isn’t his health or Xs and Os, but getting back his instincts.

“Football is a language and I’ve just got to brush back up,” he said. “I need to Rosetta Stone it a little bit.”

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