The Fratton Park loss was Pompey’s third in League One since the turn of the year, leaving them without a victory in the third tier since their 2-0 win over Morecambe back on December 11.
It also leaves them stuck in 11th in the table – 11 points off the play-offs, albeit with a game in hand on sixth-placed Oxford, and 18 points adrift of league leaders Rotherham.
When Cowley replaced Kenny Jackett in March last year, the Blues were just three points off the top six.
He managed to get his inherited side back into the play-offs – the job he was appointed to do – only for a 1-0 defeat on the final day of the 2020-21 season against Accrington to ruin another end-of-season go at promotion.
Now, with Cowley putting his stamp on Pompey following the conclusion of his second transfer window at Fratton Park and an expanding gap between the top six, McAnuff believes the Blues boss will come in for extra scrutiny.
And he used fourth-placed Sunderland’s decision to part ways with manager Lee Johnson as an example of what can happen when a manager of a big club at this level fails to meet expectations.
When asked about Cowley’s situation at the end of Monday night’s game, McAnuff said: ‘Well, you look at what happened to Lee Johnson and that’s the standard those big, big football clubs in this division expect.
‘They expect success and they demand it, so certainly, of the back of last season, the disappointment of not getting in the play-offs, that was the minimum requirement and expectation at Portsmouth Football Club.
‘And the more they fall behind that, of course, the more pressure there will be.’
Pompey can close the gap on the U’s on Saturday, when they make the trip to the Kassam Stadium (3pm).
Expected to be in the Blues squad will be former Sunderland forward Aiden O’Brien, who became Cowley’s fifth new arrival of the January transfer window on Monday.