Durant tore his right biceps in the fourth quarter of the Cowboys' 20-17 loss to Washington in overtime on Monday. He was leading Dallas with 61 tackles.
The 29-year-old Durant is in the last year of a two-year contract. He spent four seasons in Jacksonville and two in Detroit before joining the Cowboys.
Dobbins was a fifth-round pick out of Iowa State by San Diego in 2006. He played four seasons with the Chargers before one year with Miami and the last three in Houston. He was cut at end of training camp by Atlanta this year.
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