I found this reported on August 29th...
Tapper (back) has not practiced in the past several weeks but could be nearing a return, Jon Machota of the Dallas Morning News reports.
Tapper has been dealing with some back soreness that is not believed to be too serious. If all goes according to schedule, the
Cowboys believe that Tapper could be back practicing within the next few days. Dallas is expecting its fourth round pick from April's draft to provide the team with added depth on the defensive line during the 2016 campaign.
I read "shot" and I think herniated disk.
But "back soreness that is not believed to be serious" doesn't scream herniated disk to me.