Ndombele, 22, has been linked with both Premier League clubs this season and told Le Progres (h/t Richard Fay of the Manchester Evening News) he's yet to make a final decision on whether he'll stay at Lyon.
He said: "As I told my agents and the club, I'm not fixed yet, I did not make a decision. Of course I could see myself staying with Lyon, the club will be in the Champions League. But I've not asked the question to stay or not, and I've not spoken with the new staff."
Bruno Genesio stepped down as Lyon manager at the end of the season and was replaced by former Arsenal and Barcelona defender Sylvinho, per Marca. In another backroom change, ex-Lyon fan favourite Juninho Pernambucano has taken over as sporting director.
It could be telling that the player is yet to make contact with the new figures in charge, who will surely want to keep hold of Ndombele ahead of their return to the UEFA Champions League.
Ndombele played 66 minutes of France's 2-0 friendly win over Bolivia on Sunday in just his second senior international start. The playmaker made his national team debut in October 2018 and is already making his mark for Les Bleus:
United have perhaps the most motivation to sign the creative talent considering Ander Herrera will leave on a free this summer and could be joined by Juan Mata, whose contract is set to expire this month.
There's also speculation around the future of Ndombele's France team-mate Paul Pogba, per Dan O'Toole of the M.E.N., and he could be a key tool in attracting his countryman to Old Trafford.
However, bitter rivals City are just coming off their second successive Premier League title win and look the more appealing destination, particularly as United will be in the UEFA Europa League next term.
City may need to replace Ilkay Gundogan—whose contract expires in June 2020—in the foreseeable future. However, TalkSport reported he'll be allowed to run down his deal and leave for free next year rather than be sold this summer.
Ndombele may be on the verge of a Lyon exit, but the player didn't allow standards to drop in what could have been his send-off appearance for the club. He recently scored the winner in the 3-2 triumph against Nimes in their last Ligue 1 match of the season as Lyon secured a third-place finish.
Statman Dave analysed his numbers from that result and illustrated the balance Ndombele possesses:
Lyon president Jean-Michel Aulas previously indicated he wouldn't have an issue selling the player to French rivals Paris Saint-Germain should they meet his valuation, per Fay's report:
"I am in negotiations with the biggest European clubs, and I revived the PSG talks myself to tell them to make sure not to feel excluded.
"I thought it was time to give PSG direction because PSG will gain more to use French clubs.
"If PSG aligns with the proposals we have and Tanguy agrees, obviously it would be nice if he goes to PSG."
Ndombele has four years remaining on his Lyon contract and is one of the team's most valued stars, but the player hasn't discouraged the likes of United and City from stepping up their alleged interest.