The Red Devils were heavily linked with the German playmaker last month, but were ultimately unable to push through a deal before the deadline passed.
However, they have been given major encouragement from the Bundesliga champions to mount a fresh move in six months time, with manager Pep Guardiola refusing to rule out the possibility of selling his star.
A new United swoop has been talked about, but now it appears that cross-town adversaries City are also keen.
The Sky Blues are fans of Kroos, and are keen to add him to their ranks as they continue their quest to become one of European football’s true giants.
The 24-year-old is values at around £25m, and could be open to a switch away from the Allianz Arena where competition for a starting berth is intense.
Although United can offer guaranteed first-team action, City are hopeful that their rivals will miss out on Champions League qualification, which would give them a major advantage in negotiations.