Terrell Thomas yesterday appeared at the Giants’ facility and spoke with general manager Jerry Reese, coach Tom Coughlin and defensive coordinator Perry Fewell. He reports all three said they envision him returning to the Giants as a cornerback. “But if not, maybe there’s a nickel safety role,’’ Thomas said, recalling all three conversations came to the same conclusion: “Either way, we just want you on the field.’’ At this point, the “where’’ is not a concern for Thomas and the Giants. Cornerback or safety will be sorted out at another time. It’s getting on the field, and staying on the field, that is the daunting challenge. Thomas, on the mend again and attempting yet another comeback, is currently rehabbing from the third knee reconstruction to his right ACL. He is considered a long shot to make it back, but the Giants are willing to give him a chance. They tore up the four-year contract he signed last spring and replaced it with a new one-year deal that will at least give him a chance to prove he’s physically able to return to the NFL. Thomas, 28, was due a $6 million option bonus payable in March and, coming off the injury, was not going to see any of that money. He is considered to be an extreme medical risk, with two ACL injuries in the past two years after tearing it the first time in 2005 while at USC. The only NFL player known to ever make a successful comeback from three ACL reconstructions is Panthers linebacker Thomas Davis. “I’m blessed and happy to have another opportunity to play football, especially with such a loyal organization, the one I started my career with,” Thomas said. “For them to give me another opportunity to prove myself, I feel very blessed.” Thomas missed the entire 2011 season after injuring the knee again in the preseason and appeared ready to reclaim his starting job until he aggravated the knee last summer, suffering a partial tear that required another surgical procedure and another missed season. He has not played in a regular-season game since Jan. 2, 2011, the final game of the 2010 season.