Jose Mourinho's hopes of bringing in his two main targets this summer were dealt a blow as one of them signalled his intention to remain with his club.
Sportsmail reported last week that the 29-year-old had been offered to United after his move to Paris Saint-Germain collapsed.
Asked about the rumours surrounding Boateng, Bayern team-mate Ribery responded: 'I've been playing with Jerome for many years now.
"In the World Cup and recent seasons, I think he's been atrocious at times with his defending".
Goalkeeper Manuel Neuer added that Boateng "would be missed" if he left, while David Alaba echoed those remarks.
It has been a disappointing summer so far, with major areas in the first team in desperate need of investment and transition; with the fanbase not willing to give Jose Mourinho any patience, he will need to hit the ground running and his insistence on senior players is therefore natural.
'We'd all be sad, ' the Austrian said.
"If we don't make our team better, it'll be a hard season for us", Mourinho told MUTV after United's 1-0 defeat to Bayern Munich on Sunday. Is it too much to demand that the best-paid managers in the world should be able to make a talented group of players into something greater than the sum of their parts?
"The other clubs that compete with us are really strong and have already fantastic squads".
Negotiations for Harry Maguire and Toby Alderweireld are becoming increasingly hard, sources said, leaving Woodward to turn his attention to German defender Boateng, who is likely to cost in the region of £50 million. Or they are investing massively like Liverpool, who are buying everything and everybody.