The website, which has produced a handful of articles but is still not up and running, was expected to launch in summer 2015.
Whitlock will remain at ESPN and his work will be featured "across ESPN platforms."
Deadspin's Greg Howard wrote a scathing article about the site in April. It depicted a organization plagued by problems caused by Whitlock's managerial style.
Here's the ESPN press release:
As we continue to move forward in the process of creating The Undefeated - a new ESPN site focusing on race and sports - we have collectively decided to make some structural adjustments that will maximize the skill sets and strengths of our team, leading to the best possible output for the site and for all of ESPN. To that end, Jason Whitlock will now be entirely focused on what he does best: creating distinctive and compelling content, which will live across various ESPN platforms. Jason's thought-provoking perspective has always been a hallmark of his work and this will allow him to completely devote his time and energy to that. As a result, he will make significant contributions to multiple ESPN entities and programs. Since returning to ESPN, Jason has been instrumental in assembling the foundation of a strong editorial team, formulating the vision for the project and collaborating with our digital product team to develop the blueprint for the site.
Leon Carter - an experienced leader in journalism who officially joined the site in January after leading staffs at the New York Daily News and ESPNNewYork.com - will assume all day-to-day management of the site's editorial processes and personnel on an interim basis.