The 54-year-old saw his fledgling reign at St James' Park suffer another body blow on Wednesday when Sky Bet Championship side Sheffield Wednesday dumped the Magpies out of the Capital One Cup.
McClaren insisted from day one that his masterplan for success on Tyneside would take time to implement, but fans battered into submission by years of under-achievement and - perhaps worse - a perceived lack of ambition, are rapidly losing patience with a project which looks increasingly flawed.
With resurgent Chelsea heading for St James' on Saturday ahead of a trip to current Barclays Premier League leaders Manchester City, the chorus of disapproval could yet grow in volume, although McClaren is adamant that victory over Jose Mourinho's men would dramatically change the febrile atmosphere threatening to engulf the club.
Barclays Prem
15 Chelsea 7
16 So'ton 6
17 A Villa 4
18 Stoke 3
19 Newcastle 2
20 S'land 2
He told nufcTV: "Do we fear it? Do we say we don't want to play in that? We have got to. We have got to get people ready for Saturday, ready to fight, and one result turns it around.
"You have got to say and you have got to believe - which I do - that could be Saturday."
Newcastle United
Newcastle 0 - 1 Sheff Wed
Newcastle 1 - 2 Watford
West Ham 2 - 0 Newcastle
Newcastle 0 - 1 Arsenal
Newcastle 4 - 1 Northamptn
Man Utd 0 - 0 Newcastle
Swansea 2 - 0 Newcastle
Newcastle 2 - 2 So'ton
Newcastle 0 - 1 M'gladbach
A win over Chelsea may well have the desired effect, and the Blues have lost on each of their last three visits to Tyneside.
However, those Newcastle teams, whatever their failings, could score goals; this one, at least at the moment, cannot, and worryingly, it cannot defend either.
Fans have directed their anger in recent years at owner Mike Ashley and a recruitment policy based on hunting out bargains from basements in which few other clubs were shopping.
For every Yohan Cabaye or Mathieu Debuchy unearthed by chief scout Graham Carr, there has been a series of failures - some of whom remain on the books and unwanted elsewhere.
But this summer, Ashley sanctioned significant investment to the tune of more than £52million, and it is the way in which that money has been spent by managing director Lee Charnley which is now coming under scrutiny with Chancel Mbemba, Georginio Wijnaldum, Florian Thauvin and Aleksandar Mitrovic yet to justify the outlay.
Of that quartet, all but the suspended Mitrovic started against the Owls and played their part in yet another one-dimensional, one-paced and ultimately impotent display as Lewis McGugan fired the visitors - who made 10 changes - to a 1-0 victory.
Debutant Kevin Mbabu, who replaced Daryl Janmaat at the break after he complained of illness, said: "We are all disappointed because we had chances to score and we didn't score. We were better than the opponents and we are all disappointed that we didn't win.
"Everybody needs to stay positive and fight. Now this game has gone, now everybody needs to focus on Chelsea and we all have to think we are able to win against this team."
McClaren will have Mitrovic back from his three-game ban and will hope his presence will prove one of the missing ingredients in a squad already riven by injury and sickness just weeks into the campaign.
The former England boss said: "We have got to take a roll call and have a look at things. I don't think it matters what we do over the next two days - it's about mentality now.
"It's about players who stand up and want to fight and want to be out there and want to turn it around, because that's what's needed - nothing else."
THE TOON'S GREATEST 100 PLAYERS ... EVER!
AMAZON: http://www.amazon.co.uk/The-Toons-Greatest-Players-EVER/dp/132629685X
This book is a collection of the 100 Greatest Newcastle United players of all time, as voted for by NewcastleUtd-Mad.co.uk readers and a panel of journalists who contribute to the website. The players are in an order of five-per-chapter, counting down from 100 to Newcastle United's greatest ever player (as viewed by the author), but the whole point of the book is for YOU (the reader) to decide who goes where. The list is not, by any means, definitive. As with all books of this nature, whether it be "Greatest Albums"; "Best Movies Of All Time"; or "Top 100 Pin-Ups Of The Year" ... no two people have exactly the same opinion. There will be controversy over who is on the list, and chances are, more controversy over who is not. Here are the best of the best. I have painted the picture with each player's profile. Where they end up in the league of NUFC's Greatest is up to you. Because YOU have the final word.
Otherwise ... if you want a signed copy (for a birthday, etc) for £9.95 and no postage ... you can meet me before a match and I will bring a copy along.
Get in touch: Kevnumad@fsmail.net
NEWCASTLE UNITED
Fri 10th July (8pm BST)
Gateshead FC 0 Newcastle Utd 1 (Cisse pen)
(First half): Darlow, Janmaat, Haidara, Lascelles, Williamson, Anita, Colback, Gouffran, Cisse, Sissoko, De Jong. (Second half): Woodman, Bigirimana, Satka, Good, Ferguson, Tiote, Obertan, Aarons, Perez, Armstrong, Riviere.
Tue 14th July (8pm CT)
Club Atlas (MEX) 2 Newcastle Utd 1 (Sissoko)
Krul (Darlow 46); Janmaat (Bigirimana 72), Williamson, Lascelles, Haidara (Ferguson 72); Anita, Colback; Sissoko (Obertan 72), de Jong (Perez 72), Gouffran (Aarons 72); Cisse (Armstrong 72).
Sat 18th July (8pm UTC)
Sacramento Republic FC (USA) 0 Newcastle Utd 1 (og)
Krul (Woodman 46), Janmaat, Williamson, Lascelles (Taylor 46), Haïdara, Anita, Colback, Sissoko, Obertan (Aarons 69), de Jong (Perez 69), Cissé (Wijnaldum 69).
Tue 21st July (7.30pm UTC)
Portland Timbers (USA) 4 Newcastle Utd 3 (Wijnaldum, Aarons 2)
Darlow (Woodman 46), Bigirimana, Satka, Ferguson, Aarons; Abeid (Anita 65), Wijnaldum (Janmaat 46), Gouffran (De Jong 76), Sissoko (Obertan 46), Ayoze, Cisse (Armstrong 46).
Sun 26th July (1pm BST)
Sheffield United 2 Newcastle Utd 2 (Wijnaldum, de Jong)
Krul, Janmaat, Williamson, Taylor (Lascelles 69), Haïdara, Anita (Obertan 59), Colback, Sissoko (Abeid 80), Wijnaldum (De Jong 73), Perez (Aarons 45), Cissé (Armstrong 80)
Wed 29th July (7.45pm BST)
York City 2 Newcastle Utd 1 (Perez)
Darlow (Elliot HT); Bigirimana, Lascelles, Satka, Ferguson; Abeid, Gouffran; Aarons (Kemen 59), De Jong, Perez; Mitrovic (Suddick 70)
Sat 1st August (3pm BST)
Newcastle Utd 0 Borussia Mönchengladbach 1
Krul, Janmaat (Mbemba 62), Williamson, Taylor, Haïdara, Anita (De Jong 75), Colback, Sissoko (Perez 81), Obertan (Aarons 62), Wijnaldum, Cissé (Mitrovic 62).
Sunday August 9
NEWCASTLE UTD 2 SOUTHAMPTON 2 (Cisse, Wijnaldum)
Krul, Janmaat, Mbemba, Coloccini, Haidara; Colback, Anita (Tiote, 67); Sissoko, Wijnaldum (De Jong, 81), Obertan; Cisse (Mitrovic, 75). Subs not used: Darlow, Taylor, Aarons, Perez.
Saturday August 15
SWANSEA CITY 2 NEWCASTLE UTD 0
Krul, Janmaat, Mbemba, Coloccini, Haidara, Anita, Colback, Sissoko (45' Taylor), Wijnaldum, Obertan (82' Mitrovic), Cisse (54' Aarons). Subs: Williamson, Perez, Tiote, Darlow
Saturday August 22
MANCHESTER UTD 0 NEWCASTLE UTD 0
Krul, Mbemba, Taylor, Coloccini, Haidara, Anita, Colback, Perez (78' Tiote), Wijnaldum, Obertan (69' Thauvin), Mitrovic (88' Cisse).
Subs: Williamson, de Jong, Aarons, Darlow
Tuesday August 26
NEWCASTLE UTD 4 NORTHAMPTON TOWN 1 (Thauvin, Janmaat, de Jong, Williamson
Darlow, Janmaat, Lascelles, Williamson, Haidara (78' Toney), Tiote, Gouffran, Aarons, de Jong, Thauvin (65' Mitrovic), Perez (72' Colback).
Subs: Dummett, Wijnaldum, Mbemba, Elliot.
Saturday August 29
NEWCASTLE UTD 0 ARSENAL 1
Krul, Janmaat, Mbemba, Coloccini, Haidara, Anita (72' Perez), Sissoko (78' Cisse), Wijnaldum, Thauvin (87' de Jong), Mitrovic
Subs: Obertan, Tiote, Darlow, Taylor
Monday September 14
WEST HAM UTD 2 NEWCASTLE UTD 0
Krul, Janmaat, Mbemba, Coloccini, Haidara, Anita (60' de Jong), Colback, Sissoko, Wijnaldum (79' Aarons), Thauvin (60' Perez), Cisse Subs: Gouffran, Obertan, Lascelles, Darlow
Saturday September 19
NEWCASTLE UTD 1 WATFORD 2
Krul, Janmaat, Mbemba, Coloccini, Haidara (80' Aarons), Wijnaldum, Colback, Thauvin (88' Obertan), Sissoko, Perez, Cisse (45' de Jong)
Subs: Williamson, Anita, Lascelles, Elliot
Wednesday September 23
19:45 Newcastle United v Sheffield Wednesday (League Cup)
Saturday September 26
17:30 Newcastle United v Chelsea