The Magpies are struggling in 14th position in the Premier League, with fan discontent growing as boos rang around St James’ Park following their 2-1 defeat to Bournemouth at the weekend.
The slump is a major concern, coming on the back of a campaign in which they enjoyed Champions League football and aimed to repeat the feat next season.
Flashscore has already reported concerns over the squad potentially breaking up, with Anthony Gordon, Sandro Tonali and Tino Livramento among those tipped to leave this summer.
Now, attention has turned to head coach Howe, with insiders revealing to Flashscore that there is a very real possibility he could leave the club.
Newcastle, owned by the Public Investment Fund - Saudi Arabia’s sovereign wealth fund - have big ambitions. And missing out on European football would represent a significant setback in their bid to establish themselves among English football’s elite.
No decision has been made on the future and relations remain good between all parties, but insiders do believe that Howe future conversations could lead to a parting of ways at the end of the season.
Should the managerial position become vacant, sources believe Mourinho will be among the leading contenders for the role. His profile and proven track record of winning trophies align with the ownership group’s vision.
It is understood Newcastle also have a long standing interest in former Premier League title winning boss Mancini.
Mancini, 61, is currently in charge of Qatar based side Al-Sadd but has a profile and pedigree that appeals to Newcastle.
Other names, including current US men’s national team coach Mauricio Pochettino and Bournemouth's Andoni Iraola, may also come under consideration if Howe leaves.
The official message out of the club is that they retain belief in Howe but this is a defining moment for Newcastle, who have five games remaining to salvage a disappointing season.
And overall the expectation is that significant changes could be heading to Tyneside this summer.