Walgreens Boots Alliance has chosen veteran health care executive Tim Wentworth as the company’s new chief executive.

Wentworth is the former CEO of the nation’s largest pharmacy benefits management company, Express Scripts, which was acquired by Cigna in 2018. He stayed on and served as chief of Cigna’s health services, before retiring at the of 2021.

“What made me decide to come back was a chance to lead this iconic brand and company at a time when it’s not in a steady state,” Wentworth told CNBC. “It’s a massive platform… they touch almost 10 million people a day.”

Wentworth will start on Oct. 23, almost two months after Roz Brewer stepped down as CEO, at a time when the company is facing a number of challenges in trying to transition to becoming a provider of health services beyond the pharmacy counter.

Under Brewer’s tenure, Walgreens took a major stake in primary care provider VillageMD, acquired specialty pharmacy provider Shields Health, as well as homecare provider CareCentrix. Trying to integrate and scale the businesses has pressured Walgreens’ earnings.

The transition has come at a time when pharmacy revenue has been pressured by falling demand for Covid vaccines and over-the-counter tests. In June, the company’s third-quarter profits missed Wall Street estimates for the first time in three years.

Walgreens’ board has said they were intent on hiring an executive with deep health experience who could rein in all of the new services.

“I came from one of the great efficiency companies at Express Scripts — I mean, we were built to drive out waste from health care and and we looked at everything through that lens. And that has to do by starting with our own cost structure, and there’s no question inside this company that’s every bit as important,” said Wentworth.

Walgreens’ executive chairman Stefano Pessina said Wentworth “is an accomplished and respected leader with profound expertise in the payer and pharmacy space as well as supply chain, IT and Human Resources. We are confident he is the right person to lead WBA’s next phase of growth into a customer-centric healthcare company.”

The company’s core pharmacy business is also facing challenges. This week, pharmacists in several cities have walked off the job to protest understaffing at pharmacies which the non-union workers say endangers patients. 

Wentworth says during Covid the drugstore chains pivoted quickly to become major providers of vaccines and supported patients with information.

“When you’re in a business that’s having to respond that quickly to something that is that unusual. You don’t get it all right. And I have no doubt that the leadership at Walgreens is taking a look and listening to their folks,” he said. “As a leader, I can tell you, there’s nothing that motivates me more than ensuring every employee feels like they’re supported in that mission.”

Walgreens is set to report fourth-quarter earnings on Thursday.