Rodri has been heavily linked with a move to the Premier League in recent weeks.
Spanish newspaper Marca today claimed Rodri has told Atletico Madrid he will leave the club this summer.
The holding midfielder has informed Atletico CEO Miguel Angel Gil Marin of his decision.
And Spanish football expert Balague has confirmed United are battling Manchester City and Bayern Munich for Rodri, 22.
However, City and Bayern lead the race for Spain international.
He tweeted: “As expected Rodri will leave AtM -wanted by City, Bayern and even United, the first two favourite.
“They will get a (Sergio) Busquets type (exceptional defensive positioning, good delivery of ball) but not yet at his level.
“MUFC’s analysis suggested bit slow in reaction and awareness.
“For #MCFC the plan would be to play mostly (Ilkay) Gundogan and Rodri in holding midfielder role, with Fernandinho sharing duties there and as a third centre-back.”
United are expected to splash the cash this summer, with Ed Woodward fully behind Ole Gunnar Solskjaer.
The Red Devils have already signed Daniel James from Swansea – and Solskjaer is keen to add more new faces.
United are in for a new centre-back and a midfielder, with Harry Maguire topping their defensive wishlist.
Leicester are demanding £90m for the England international, however, United are currently refusing to meet their asking price.
United may also need to replace Paul Pogba at Old Trafford.
The France international has hinted he could leave United this summer, claiming he needs a new challenge.
Should the Red Devils cash in on Pogba, Solskjaer will need midfield reinforcements before the start of next season.