Newcastle United’s chief executive, Darren Eales, is to step down after being diagnosed with a chronic form of blood cancer. The 52-year-old will remain in a post he has held since August 2022 until a successor is appointed.

“Being CEO of Newcastle United is an extraordinary privilege and I am incredibly proud to be part of the club’s exciting journey,” Eales said. “However it has become apparent to me that now is the right time to make this decision so that I can prioritise my health and my family.”

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As the first chief executive appointed in the wake of Newcastle’s £300m takeover by majority Saudi Arabian owners, Eales has been at the helm as Eddie Howe’s side finished fourth in the Premier League in 2022-23 and reached that season’s Carabao Cup final. More recently, he has been involved in this summer’s departures of the minority co-owners and directors Amanda Staveley and her husband, Mehrdad Ghodoussi, and the recruitment of Paul Mitchell as sporting director.

Newcastle’s chairman, Yasir al-Rumayyan, thanked Eales for a “significant contribution” and said: “All of us connected with Newcastle United are very saddened by this news.”

Eales, a Cambridge law graduate who served as Tottenham’s director of football administration and the chief executive of Atlanta in Major League Soccer, is keen to ensure a smooth transition. “In the short term it will be business as usual in terms of running the club’s day-to-day operations and I will give my full support to a transitionary period that will enable the board to carefully assess and appoint my successor,” he said.

More immediately, Howe admits he faces “difficult decisions” as he contemplates dropping some of Newcastle’s biggest, yet underperforming, names for Manchester City’s visit on Saturday. Bruno Guimarães, Joelinton and Anthony Gordon are among established first-team players out of form as Howe’s side struggle to recapture their intensity.

“Given a blank sheet of paper it wouldn’t be difficult for me to write my best team down,” Howe said. “The problem is you have to justify your selection so those players have to be in their best moment and best form. What you can’t do is pick a team that doesn’t deserve to play … I’m at that stage now where I’ve got some difficult decision to make.”

Howe said the team had “to get back to our very best levels in terms of our energy and running” and that he needed a return to form from Guimarães. “It’s difficult with some of the internationals, especially players that have to travel such big distances because when they come back, they’re fatigued,” he said. “But Bruno knows he has to try and give more to the team. I back his quality and character. He’s the heartbeat of our team, we need Bruno back to his best.”

The same applies to a few others, notably the previously immensely influential Joelinton and Gordon. “If one player in the XI doesn’t follow the plan or deliver what you ask the whole plan falls apart, especially at this level where teams are good enough to expose one weak area,” said Howe, who is expected to give the midfielder Sandro Tonali his first start since a 10-month suspension for breaches of betting rules. “If individuals aren’t performing you’re going to suffer. We need people to step up and have a galvanising effect on the group.”

Alexander Isak has also underwhelmed in recent weeks but, in mitigation, the striker is playing on pain-killing injections for a broken toe and is touch and go to feature against City.

Howe said “all is good” in his relationship with Paul Mitchell, the sporting director, after the pair held positive talks last week aimed at ending their recent hostilities.