The timetable for Geno Atkins' return continues to be a mystery (as if major injuries are supposed to be easy to return from).

We've heard that he'll participate during training camp "at some point" and we've heard that he won't be ready for the regular season. It's probably somewhere in the middle, yes?

Cincinnati Bengals defensive coordinator Paul Guenther told reporters at the team's media luncheon that he "believes" that Atkins will be ready for the regular season opener.

#Bengals DC Paul Guenther says he believes Geno Atkins will be ready by Week 1. Exhale, Who Dey Nation. — Coley Harvey (@ColeyHarvey) July 22, 2014

More positive reviews for Geno. DC Guenther says he sees him playing Week 1. — Paul Dehner Jr. (@pauldehnerjr) July 22, 2014

Bengals head coach Marvin Lewis expressed similar optimism.

Marvin says going to hold Geno on PUP for few days into camp to get look at him. In a good spot though. Very encouraging news. — Paul Dehner Jr. (@pauldehnerjr) July 22, 2014

Atkins suffered an ACL tear against the Miami Dolphins last year and was placed on the team's Active/Physically Unable to Perform list on Tuesday. Once he's medically cleared, he can join his teammates on the practice field. However, if the medical staff is unable to clear him by the time Cincinnati starts the regular season, he would likely join the Reserve/Physically Unable to Perform list -- preventing him from playing for the first six weeks of the season.

Atkins, a two-time Pro Bowler, earned first-team All-Pro honors in 2012 after generating 12.5 quarterback sacks -- also third-most in a single-season in franchise history.