(L-R) Actor Casey Affleck with his award for best actor in 'Manchester By The Sea' and Amazon SVP Jeff Blackburn attend the Amazon Studios Oscar Celebration at Delilah on February 26, 2017 in West Hollywood, California.

Jeff Blackburn, Amazon's SVP of business and corporate development, is taking a one-year leave in 2020, Amazon's representative told CNBC.

Blackburn, who joined Amazon in 1998, is one of the most senior executives at the company and a close advisor to CEO Jeff Bezos. He oversees a number of businesses, including Amazon's video streaming and advertising units. Geekwire was first to report the news about his sabbatical.

Amazon's spokesperson confirmed his leave in an email statement sent to CNBC.

"Jeff Blackburn has decided to take a one year sabbatical with his wife and extended family following more than 21 years at Amazon, leading everything from our third party business, to Prime Video, Amazon Studios, Amazon Music, and Amazon Advertising. Jeff's sabbatical will begin in early 2020, and we look forward to welcoming him back in 2021," Amazon's spokesperson said.

Blackburn's leave is significant, given how he's been one of the longest-serving executives at the company. He was often mentioned as one of the top candidates to succeed Bezos, if the CEO chooses to step down one day.

It's also the latest high-profile change in Bezos's S-team, his tight knit group of senior executives that see very little turnover. Last year, SVP of marketplace Sebastian Gunningham left for WeWork, while SVP of international business Diego Piacentini decided not to return to Amazon after taking a two-year leave.

Blackburn currently owns 71,000 Amazon shares, which is worth roughly $132.5 million. Among S-team members, only AWS CEO Andy Jassy, who owns 93,000 shares, has a larger ownership stake.

In 2017, during a rare on-stage interview with CNBC's Julia Boorstin at a Vanity Fair event, Blackburn explained Amazon's decision to strike a streaming deal with the NFL to carry Thursday night games for Prime subscribers. Viewers got the option of choosing between the Fox broadcast with Joe Buck and Troy Aikman as commentators, or a separate stream featuring an all-female duo of Andrea Kremer and Hannah Storm.

"For us in live sports, it's a content type that Prime members care about and they've told us they want that," Blackburn said at the event. "We've looked all different kinds of things all over the world. We actually have been for a while."