FRISCO, Texas — The Dallas Cowboys have released cornerback Nolan Carroll, the second significant free agent let go this season.

Carroll left a loss at Denver in Week 2 with a concussion and didn't play again before Wednesday's move. The eighth-year player practiced last week but was inactive in a loss to Green Bay.

The Cowboys released defensive tackle Cedric Thornton before the start of the regular season. Thornton was Dallas' biggest free agent signing in 2016, and Carroll was the biggest this year. Both came from NFC East rival Philadelphia.

Carroll signed a $10 million, three-year contract in March with $3 million guaranteed. Thornton was in the second year of a four-year, $17 million deal with $9 million guaranteed.

The Cowboys signed Justin March-Lillard to fill Carroll's spot.

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