Spears expects to be back in time for regular season opener.
"I'm doing fine," Spears said. "It's a strain, so it's going to take a while for it to get back. I know the moment I feel like I'm ready to go and I'll be going."
However, he is frustrated that it will take away from him learning the new defense under coordinator Rob Ryan.
Spears was re-signed by the Cowboys late in July after the lockout was lifted. Dallas and Spears agreed to a five year contract worth $19.2 million. Spears missed the final eight games of the 2010 season with a strained calf, so hopefully this isn't becoming a trend with Spears.
The regular season begins on September 11 as the Cowboys visit New Meadowlands Stadium to take on the Jets on Sunday Night Football.