Mirror Sport reported earlier this week that United were considering a move for Rabiot, who is out of contract this summer.
The 23-year-old looked set to join Barcelona but the deal fell through due to his £175,000-a-week wage demands and signing on-fee of £10m
But reports in Italy suggest they will have to act fast with Juventus making their move, having already signed Aaron Ramsey on a pre-contract agreement.
Tuttosport claims Juventus sporting director Fabio Paratici has been in talks with Rabiot’s representatives.
The Serie A champions have offered a contract believed to be in the region of £5.3m-a-year, which could raise to £7m related to performance-based bonuses.
However, that deal is still short of the deal Rabiot is demanding from his potential suitors.
And that could alert United, with Ole Gunnar Solskjaer eager to bring in additions in central midfield this summer.
Ander Herrera’s exit has already been confirmed, with the Spaniard expected to replace Rabiot at PSG.
Paul Pogba is set to follow Herrera out of Old Trafford, with Real Madrid boss Zinedine Zidane eager to snap up his countryman.
His wage demands could also prove to be a stumbling block with Barcelona monitoring the situation.
Solskjaer remains a big fan of Scott McTominay, who is set for a regular first-team role next term, but has reservations about other options including Fred and Andreas Pereira.