Starbucks is about to make "significant changes" to its organizational structure that could include corporate layoffs, according to an internal memo sent to employees by CEO Kevin Johnson.

"We must increase the velocity of innovation that is relevant to our customers, inspires our partners, and is meaningful to our business," Johnson said in a memo obtained by CNBC. "To accomplish this, we are going to make some significant changes to how we work as leaders in all areas of the company."

Johnson said that the executive leadership team is working with supervisors to find ways of innovating faster in a new retail environment. While some roles will be consolidated, others will be shifted, and there will be some non-retail layoffs, a source familiar with the plan told CNBC.