Cullen Jenkins knows he’s coming to a Giants team that has won two Super Bowls since 2007 and that, despite his impressive NFL resume, he is going to have to prove himself to his new team.

“It has to be something you earn,’’ Jenkins said yesterday on after signing his three-year, $8 million contract. “It’s going to take a lot of work, especially on my part, to come in and make sure I’m fitting in with the team. I have to be willing to do whatever they ask of me and help out the best I can.”

Jenkins, 32, figures to fit right in as a starting defensive tackle, replacing Chris Canty, who was released. Jenkins was a starter for the Packers on their 2010 Super Bowl championship team and spent the past two years with the Eagles before they cut him Feb. 25.

General manager Jerry Reese said Jenkins “brings the physical nature that we like and also gives us a lot of flexibility up front.” Coach Tom Coughlin said Giants players have high regard for Jenkins based on what he’s done against them as an opponent.

Jenkins has played against the Giants seven times, including four times in the past two years.

Co-owner John Mara said Jenkins “was one of the highest players we had graded of all the free agents’’ and added the pro personnel and coaching staff “all loved him.”

“As I understand it, even [guard] Chris Snee was very much in favor of signing him because he’s been such a tough opponent for him over the years,” Mara said. “He’ll give us a certain toughness on that defensive line.”