The 2019 world champion this year rejoined the Ford squad that afforded him his full-time WRC debut in 2012, essentially on a one-year deal.
It appears Tanak will once again play a key role in the silly season as teams begin to form driver line-ups for the 2024 season.
Tanak has endured a challenging return to M-Sport, headlined by a victory in Sweden and a second-place finish in Croatia, but his campaign has been plagued by a combination of misfortune and reliability that has dropped the Estonian out of the title race.
With Hyundai's Thierry Neuville the only driver from the three Rally1 teams contracted for next year, in theory Tanak could have options. Tanak has previously driven for Toyota in 2018 and 2019, before moving to Hyundai for 2020 as world champion, a tenure that ended with a year remaining on his contract last season.
However, Toyota boss Jari-Matti Latvala has previously stated he has no intentions to change his team's line-up which includes Kalle Rovanpera, Elfyn Evans, Takamoto Katsuta and part-time driver Sebastien Ogier.
Rumours circulating in Rally Finland have however linked Ogier to a move to Hyundai, although these were downplayed by team boss Cyril Abiteboul.
Hyundai is understood to be keen on offering Esapekka Lappi a contract extension while Teemu Suninen appears an option for its third car. The team is also weighing up the prospect of running a fourth car.
Asked about its driver line-up for next year, M-Sport's Millener is adamant the team would like to continue with Tanak but admitted the squad had to be realistic about its options.
"Negotiations are always easier when you win. I don't know what the other teams are doing and I don't know what options are in the other teams," said Millener.
"We have to be realistic in what we can achieve as well. We are pushing as hard as we possibly can and to go any steps further with what we are doing is hard.
"We will have to talk over the next couple of months and I don't think it is going to be a quick decision.
"I think we all don't want to lose Ott. He has been fantastic for the championship alone, but also for us to continue to have him in the team. But it is never a quick and easy answer.
"I don't know if he will go to another manufacturer or not. I don't know what Ott will do but from our side, we would love to have him in the team.
"We have made a lot of progress and we would love to continue it. We all know we can do better than what we are, and if we had a good run of luck it might be a completely different story.
"If we had few a more good results we would probably be having a completely different discussion."
Millener admitted that funding is not the main aspect but among the factors that will need to be considered to secure Tanak's services for next season.
"It is certainly going to be a contributing factor," Millener added.
"It is hard because sponsorship often comes with good results and we don't have them at the moment. You have to hope and believe that the sponsors we do have still believe in what we can do."
Aside from its desire to retain Tanak, M-Sport has today announced a restructuring of its leadership team. Long-serving commercial director John Steele will leave the role after 38 years, but will remain in an advisory role and will assist introduction of a new leadership team.
Working under team owner Malcolm Wilson, the new leadership team will feature existing company director Matthew Wilson, technical director Chris Williams, Millener, finance director Paul McKnespiey and M-Sport Poland board member Maciej Woda.
The WRC returns after its summer break next week with a trip to Greece for the Acropolis Rally. M-Sport's pre-event testing was unaffected by wildfire risks in the region.
