The limp defeat leaves Newcastle second bottom of the Premier League table with just 24 points and staring another relegation in the face.
McClaren spent heavily in January to bring in the likes of Jonjo Shelvey and Andros Townsend in a bid to save themselves from the dreaded drop.
Speculation rife over McClaren's future
But after the club's latest defeat speculation over McClaren's future has reached fever pitch with rumours that former Liverpool and Chelsea boss Rafael Benitez is being lined up as his potential replacement, as reported by the likes of The Guardian.
McClaren has criticised the St James' Park crowd for being 'too harsh' on his side at times this season while players seem unable to cope with the expectations from the terraces.
'Try playing for West Ham...'
Responding to a suggestion from some quarters that the Newcastle fans 'aren't creating an environment for the players to play in' Hartson told MOTD2: "Try playing for West Ham when things are going badly."
West Ham fans are a knowledgeable bunch but are also notorious for demanding a lot from anyone donning the famous claret and blue shirt.
Newcastle fans are just as passionate about their side, though, and at the very least expect to see a bit of fight and pride on display.
The former Celtic and Arsenal man, who scored 24 goals in 60 games for the Hammers between 1997 and 1999, also said he feared for Newcastle in the relegation battle.
"I think Sunderland have a ready-made goalscorer in Jermaine Defoe and Sam has been over the course and been there before," he added.
"They've spent £80million Newcastle ... for me it's nowhere near good enough, Newcastle should be doing better than that especially having brought in all those players."