For those who are eagerly awaiting CM Punk's Ultimate Fighting Championship (UFC) debut, well, here's a not so good news. Apparently, the former World Wrestling Entertainment (WWE) heavyweight champion has suffered a shoulder injury during training, which will affect the timeline for his UFC debut.

Punk's coach Duke Roufus revealed that he has been sidelined for the time being following an injury he sustained during a scramble in training.

Punk is scheduled to see a physician regarding the extent of his injury this coming Oct. 14. Regardless, Roufus is upbeat despite the minor setback.

"He was doing great before that. His progress has been good. He's got a great attitude and he's a hard worker. He got a place in Milwaukee where he lives all week when he's here training, so he's in it to win it," says Roufus in an interview with ESPN.

Punk originally signed a deal to make his UFC debut in December, but it seems that the 36-year-old mixed martial artist is not yet fit despite being in deep training.

"The injury throws us back one month. We had a ballpark. We were looking at mid- to late-spring. Now, we'll just have to see how he comes back from the injury," says Roufus via Yahoo Sports.

The year 2016 would be the likely time when Punk could be seen entering the Octagon, and Roufus believes the perfect setting could be at UFC 200, which is being planned to be held at a 20,000-seat area at the Las Vegas Strip.

Then again, the final decision on whether or not Punk will indeed be ready is still up in the air. At his age, not many are sold that Punk can make the same impact he did in the WWE. Regardless and being the competitive person he is, Punk seems determined to prove critics wrong.

But to make all that happen, Punk needs to make sure he is ready. Right now, it seems he isn't, and the latest shoulder injury just moved his debut back a bit.