We reported last night that Robert Downey Jr. was dropping out of director Jon Favreau's Cowboys and Aliens and now we know why. Entertainment Weekly is reporting that Downey Jr. left Favreau's film to reprise his role in a Sherlock Holmes sequel.

The site is reporting that a sequel has not been greenlit as of yet, but is still being put on the fast track, with Warner Bros. ordering a script from Kieran and Michele Mulroney and moving towards a shooting date in June, which is when Cowboys and Aliens is set to start shooting.

RELATED: Has Robert Downey Jr. Finally Started Production on Sherlock Holmes 3?

Be sure to stay tuned as we'll certainly be providing more updates on the statuses of both a Sherlock Holmes sequel and Cowboys and Aliens as soon as we have more information.