As fans await "Sherlock" season 4, work on "Doctor Who" season 8 and Benedict Cumberbatch's busy schedule are causing concerns.

Currently, executive producer Steven Moffat is busy working on "Doctor Who" season 8, which is filming episode 4 and 5, which means "Sherlock" season 4 is can only be on the back burner for the time being.

"The idea of growing older with it would be great. But it is hard to get everyone back together, because they have become extremely famous -- except for us," says Mark Gatiss according to the Hollywood Reporter.

Currently, "Sherlock" season 4 is slated for 2016, which can only truly be confirmed once "Doctor Who" finishes filming its current season.

But if "Sherlock" is to shoot during 2015, it just got a little bit harder, as main star Benedict Cumberbatch will be taking on Shakespeare in the middle of the year.

According to Carter Matt, Benedict Cumberbatch will play the lead role in "Hamlet" at the Barbican Theatre in London. The 12-week run will take place in the summer or fall of 2015.

Given the timing, it is possible Benedict Cumberbatch's schedule will once again affect or possibly even delay "Sherlock" season 4, but to what extent remains to be seen.

But it's not simply Hamlet and Sherlock that demands Benedict Cumberbatch, but also "Frozen 2!"

During an interview, "Frozen" directors Jennifer Lee and Christopher Buck spoke of possible celebrities they would want in a sequel. In addition to Jamie Foxx and Matthew McConaughey, Lee also named Benedict Cumberbatch as part of their dream cast.

Between "Sherlock" and the stage, hopefully Benedict Cumberbatch has time for "Frozen 2" as well!