Rarely seen Joe Flacco is apparently the Ravens' 'top-secret Weapon X'

OWINGS MILLS, Md. -- Baltimore Ravens quarterback Joe Flacco hasn't stood on the field and watched one practice since being sidelined with a back injury. Flacco hasn't been on the sideline for any of the preseason games either.

Unless you bump into him in the hallway of the Ravens' facility, Flacco has become the team's invisible man, or an X-man, depending on you ask.

"Top secret, baby! Top secret," wide receiver Mike Wallace said. "We can’t give you any glimpses of Joe. When he comes back, you all are going to see. He has gained like 30 pounds of muscle, he is running like a 4.5 [40-yard dash] now. He is like Weapon X. He is under wraps right now, but when he comes back, it is going to be crazy."

Flacco hasn't practiced in this year's training camp because of the back issue. After coach John Harbaugh ruled out Flacco from practicing, the earliest Flacco would return is Aug. 27, which would give him two weeks to prepare for the regular-season opener in Cincinnati, set for Sept. 10. The Ravens, though, haven't announced definitively when Flacco will come back.

At the start of camp, doctors told Flacco and the Ravens that he would need about a week of rest for his back issue to subside. The 32-year-old now will miss at least four weeks of practice.

Wallace believes the offense will have enough time to get in sync with Flacco.

"Joe is a vet. He has been 10 years in the game," Wallace said. "He has won Super Bowls, he has been in every situation. He might need to knock a little rust off, but hopefully we can knock that out in those days of practice before Week 1. I think once we get into the game all it will take is a couple plays and then you feel like you are in the game. It is like, ‘OK, let’s go.’ But, he is a vet. He will be fine."

Wallace also said there isn't a greater emphasis on learning in the team meetings because Flacco and other starters on the offense haven't been able to practice.

"Just because one man is not here, it doesn’t mean you focus more or focus any less," Wallace said. "You go about the business the same way you should and that is with tunnel vision. Every day, I don’t think you should change your approach because one guy is in or one guy is out. If you are doing that, you are wrong. You should have that same mindset every day [to] focus in the classroom and focus on the field to get better and precise at everything."