Professor X isn't the kind of character who's going to let a little thing like a bullet in the spine keep him from getting around.

As we saw at the end of X-Men: First Class, James McAvoy's Charles Xavier found himself in an X-marked wheelchair similar to the one used by the future version of the character played by Patrick Stewart in the first three X-Men films. The upcoming First Class sequel, Days of Future Past, will feature both actors as Professor X, although we're not exactly sure how the two will share the screen, if at all.

While fans try to figure out what Days of Future Past will entail, director Bryan Singer is overseeing pre-production of the film. If you follow his Twitter account, you'll notice he sends out the occasional behind-the-scenes image -- and just yesterday, he tweeted the photo at right along with the line, "Hello old friends #XMen #DaysofFuturePast."

X-Men: Days of Future Past stars McAvoy, Michael Fassbender, Nicholas Holt, Jennifer Lawrence, Ian McKellen, Hugh Jackman, Anna Paquin, Ellen Page and Shawn Ashmore. The film opens July 18, 2014.