Fans of the Giants, even in good times, are frequently exclaiming, “We need linebackers!’’ and there’s no doubt that’s again the case this offseason. The Giants Thursday retained a player who may not excite the fan base very much, but Keith Rivers is back and will be competing for a starting spot.

Rivers didn’t make much of an impact in his first season with the Giants, arriving with fairly high expectations after a mostly disappointing four-year run with the Bengals. Rivers, an unrestricted free agent, didn’t do anything to warrant much interest in the open market and so he returned, signing a one-year contract.

The Giants also added some depth to their defense, signing safety Ryan Mundy, who played in every game the past four seasons for the Steelers, mostly on special teams. Mundy doesn’t replace Kenny Phillips, who wasn’t expected back and yesterday signed a one-year deal with the Eagles, as restricted free agent Stevie Brown and second-year Will Hill return at safety alongside starter Antrel Rolle. Cornerback Terrell Thomas also could be an option at safety if his knee holds up.

Rivers, 26, entered the NFL as a 2008 first-round pick out of USC, the ninth overall selection in the draft. Rivers this past season played in only 11 games, starting six. He was productive (44 tackles) when he was on the field, but battled through nagging hamstring issues.

The Giants have a glaring need for a middle linebacker, but that’s not where Rivers fits in. He will be given a chance to win a starting outside linebacker job, likely as a replacement for Mathias Kiwanuka, who shifts back to his natural defensive end role with Osi Umenyiora looking elsewhere. Jacquian Williams is the favorite to move into the starting spot vacated when Michael Boley was released. Last season’s starter in the middle, Chase Blackburn, is an unrestricted free agent and looking for more than a one-year commitment.