Mark Fell will be absent from the technical area when Lancaster City take on FC United of Manchester on Saturday.
The Dolly Blues manager is taking a break from the job on health grounds, with his No.2 Graham Lancashire taking over the reins.
City made the announcement on Tuesday evening and it came as a shock.
A brief statement on their official website read: “Lancaster City Football Club can confirm that manager Mark Fell will be taking a temporary break from his role on health grounds.
“During this break Graham Lancashire will step up to take overall charge of the squad.”
Fell took the Dolly Blues job in October last year after the resignation of Phil Brown.
They were bottom of the NPL Premier Division at the time but he guided them to the safety of mid-table.
While they were knocked out of the FA Trophy last Saturday by Stourbridge, losing 2-1 in a replay at Giant Axe, their form of late has been excellent.
Lancaster were 13 games unbeaten in all competitions before the Stourbridge game, that run including a 1-0 win at leaders South Shields. They are in second place in the table going into the weekend.
Lancashire stepping up to replace Fell should be a smooth transition. The former Preston, Wigan and Burnley striker worked with Fell at Ramsbottom previously.
“Nothing is going to change really, there is a good staff here who work well together,” said Lancashire. “I’ve stepped in a couple of times before when Mark has been away.
“We’ll be without Mark for a couple of weeks and we will just take things from there.”
He has a tough first game on his hands, with Saturday’s hosts FC United on a decent run of form. Managed by former Bamber Bridge boss Neil Reynolds, they are unbeaten in eight games.
Lancashire said: “It will be a tough game at FC United, their results recently speak for themselves. But we are in good form ourselves and the lads have been playing very well.”
He will hope to have Matty Blinkhorn back for Saturday, a hamstring injury having kept the striker out of the Stourbridge game. Paul Dawson came on as a substitute in that game having had a toe injury – it was feared he had broken it, however that was not the case.