Former Giants receiver Thomas retires
Thomas, 25, is perhaps best known for recovering two fumbles in the Giants' NFC championship game win over the San Francisco 49ers in January.
Thomas was a second round pick of the Washington Redskins in 2008. He was in Chicago Bears camp this season before abruptly calling it a career.
"I have decided to retire from the NFL," he wrote on Twitter.
He told the New York Daily News he has other goals in life.
"I mean, you know, football, it's just a game," he said. "I enjoyed playing it for a while. I had my greatest moments obviously with the Giants. I felt my spirit going other ways. I just felt it was a good time to let the game go. I think this is the perfect time."
Thomas struggled the first four years of his career and spent last season returning kicks for the Giants. He lost that job during the season but continued to contribute on special teams, especially in the playoffs.
Thomas, who starred at Michigan State, said he is focused on planning his upcoming wedding, spending time with his son and giving back to his hometown of Ann Arbor, Mich.