United would be required to pay $10m (£7.5m) to release Pochettino from the contract he signed only in August. The compensation would be higher if the Argentinian brought his own staff.
Carrick, 45, was pictured arriving at the club's Carrington training base on Wednesday. Reporting suggested clarity was more likely that day, after which the remaining pieces of the succession plan should start to fall into place.
The 54-year-old is understood to see the chance to manage United as a serious opportunity. The expectation is that he would take the job if it were formally offered.
That staff could include his longtime assistant and confidant, Jesús Pérez, who has worked with Pochettino for 16 years. Pérez's arrival would add to the sum United would have to pay.
A summit in Monaco is set to decide Carrick's future and what happens next at the club. There is an expectation within the executive and in Carrick's camp that a sacking will be ratified there and that an announcement will follow.
Large gaps remain, not least whether Carrick will be dismissed. Until that question is settled, United's next step cannot be confirmed.
Approaching a possible successor before a decision on the current coach may look uncomfortable. Such talks are not uncommon in football, where clubs and agents often gauge interest before a vacancy exists.
Immediate changes have happened before. Mark Hughes was replaced at once by Roberto Mancini at Manchester City in 2009, a switch that could not have been made without earlier contact.
Carrick has overseen a disastrous start to United's season that has left the club in the relegation zone. United were knocked out of the Carabao Cup by Brighton in September.
Pochettino moved into international football by taking the USA job in September 2024. He led the co-hosts to the last 16 of the 2026 World Cup.
Confidence over a succession plan has raised the possibility that he may not take charge of the games still to come before any change is confirmed. That depends on when Carrick's position is settled.
The main issue still to be decided is Carrick's future. Pochettino is prepared to accept if United make a formal offer, but the Monaco meeting has to come first.