Insiders say Howe was already in the club’s thinking when Ruben Amorim lost his job, but Carrick’s good work as interim manager ultimately changed the situation. Carrick helped United finish strongly after taking over and impressed the hierarchy sufficiently to earn the position on a permanent basis.

The circumstances have begun to change, however, with United making an inconsistent start to the new campaign and Carrick’s position being debated publicly.

The November international break is expected to become an important point of assessment. By then, Carrick will have had a demanding run of fixtures in which United’s progress can be judged from several different perspectives.

Tottenham, Atletico Madrid, Leeds and Como all represent different tests in the coming weeks, but are also matches United regard as important and winnable.

How the team performs across those games will help determine whether the concerns surrounding Carrick develop into something more significant - or whether he can restore the momentum that earned him the permanent job.

Howe’s availability adds a tempting alternative should United eventually decide they need a change.

He has since left Newcastle, meaning a key option who was already in United’s thoughts during the Amorim situation is now unattached. 

Howe's name has begun to crop up again in relation to the United job as questions around Carrick have emerged, and sources do believe he remains a figure of interest to the club's decision-makers.

It is not something that United have to make a decision on right now, and it is important to note that no contact has been made with any other coaches or representatives at this time. The club are supportive of their current boss and extremely hopeful he guides them towards better results and performances.

But if Carrick does not make progress with his team quickly, then the situation will develop - and Howe will likely emerge as a contender.