The executive charged with spearheading innovation at Target Corp. is leaving the company as CEO Brian Cornell refocuses efforts on the core business.

The exit of Casey Carl, 41, the company's chief innovation and strategy officer, comes as Cornell hunts for quick moves to revitalize stores amid falling sales.

Carl has pushed Target to think about the direction of retail beyond the next few years, but the retailer has been dismantling a number of his projects, including a store-of-the-future concept with robots that was to be built in Silicon Valley. In their place, Target has focused on remodeling stores and lowering prices.

Cornell announced Carl's departure, scheduled for May 5, in an e-mail to headquarters employees Thursday. He is one of the most senior among the several digital- or innovation-focused executives who have exited the Minneapolis-based retailer in the past year.

Cornell said the retailer will search for a replacement who will help elevate Target's core business, vet new business ventures and create new avenues of growth.

"Innovation is alive and well at Target," Cornell wrote. "Our new leader's job will be to build upon the progress we've made. And while this leader will play a critical role in Target's innovation story, it's not a story they will write alone. Innovation must be a mind-set, an essential component of every business, every strategy and every team."

He called Carl a "true change agent" who helped Target adapt to the digital age. Carl was brought in from a merchandising role to oversee Target.com in 2011 following a number of embarrassing glitches with its website after the retailer took control of it back from Amazon.com.

Target has always been a retailer known for innovation, but mostly related to products and services such as its limited-time designer partnerships, its Redcard that gives 5 percent off every purchase, and its Cartwheel coupon app.

In his current position, Carl referred to himself as a "chief agitator" whose duty it was to not only prod Target's merchandising and marketing teams to think more innovatively, but also to help the organization look out on the horizon to see how Target could start working on ideas now that would help better position it in five to 10 years.

One of Cornell's first leadership changes after he became CEO in 2014 was promoting Carl to the role, a newly created position on his senior leadership team.

At that same time, Cornell also elevated Jason Goldberger, who was president of Target.com, to be its chief digital officer. Goldberger left the company last fall with most of his duties transferring to Chief Information Officer Mike McNamara.

In his nearly three years as CEO, Cornell has overhauled the corporate suite, with only two of the 11 executives on the senior leadership team still in place since he took over.

"When you get a new CEO, you expect a lot of turnover," said Brian Yarbrough, an analyst with Edward Jones. "But this is a lot of turnover. And some of these people are people [Cornell] promoted or brought on board. So you have to wonder if he's not feeling some pressure."

Under Cornell, Target had been showing slow but steady growth until about a year ago when traffic and sales started slipping. Target's comparable sales during the holidays dropped 1.3 percent, lower than expected, as more shoppers continued to flock to Amazon.com and amid fierce competition from Wal-Mart. Target's stock has dropped by a third in the past year from the low $80s to the mid-$50s. Shares closed at $54.64 Thursday.

In February, executives laid out a dreary forecast of low single-digit declines in comparable sales for the coming year at an analysts' meeting in New York. At the time, Cornell and his team unveiled a strategy focused on lowering prices, remodeling stores, launching or refreshing a dozen new in-house brands and overhauling its supply chain to better integrate its digital and physical operations.

Cornell recently said that the retailer can no longer afford to invest in projects that don't pay off within a few years.

Leon Nicholas, chief insights officer for Kantar Retail, said there are some concerns about Target losing some high-level digital talent. But the retailer also needs to mind the core business first, he said.

"I think this makes sense," he said. "I'm disappointed like everybody else because it does indicate that Target is more present-focused than future-focused, but I don't necessarily see that as a bad thing."

Some of Carl's projects may have been a "little too forward-thinking," Yarbrough acknowledged. But at the same time, retail is in the midst of a major upheaval, and the retailers that are winning, such as Amazon and Wal-Mart, are those that have been innovating, he said.

In his own e-mail to employees, Carl said the work he's done over the past few years has been some of the most rewarding and challenging of his career.

"It's no secret that there's been a lot of change recently at Target, and this is the right time for me to pursue what I'm most passionate about and builds upon what I've started here," he wrote.

One of Carl's deputies, Jamil Ghani, who was senior vice president of strategy, left Target earlier this year to take a job at Amazon. Jeff Jones, who was Target's chief marketing officer and a prominent voice pushing for innovation within the company, took a job at Uber last year that ended up being short-lived. And West Stringfellow, hired by Carl to be vice president of internal innovation, also recently left the company, Target confirmed.

Stringfellow was one of three entrepreneurs in residence that Carl brought into Target in 2015 to come up with new businesses and fresh ideas. One of Stringfellow's projects, a secretive start-up called Goldfish that was working on creating an online marketplace, was shut down earlier this year.

Another project spearheaded by one of the entrepreneurs was the creation of the Food + Future lab in Cambridge, Mass., aimed at bringing more transparency to the food system. It had been exploring ideas such as building farms within stores.

But in recent months, Target has been trying to divest the lab. The retailer was preparing to shut it down earlier this week until a potential offer to buy it surfaced at the last minute.

Kavita Kumar • 612-673-4113