Manchester United manager David Moyes travelled to Germany on Friday to monitor Bayern Munich duo Dante and Toni Kroos, Goal understands.
Earlier this week, the Brazilian's agent claimed the German champions were "in a race" to sort a contract extension and that United's interest in the 30-year-old has been long-standing.
Kroos, meanwhile, has seen talks over a new deal at Bayern stall, with chief executive Karl-Heinz Rummenigge admitting the club are keen to extend his contract which expires next year.
Bayern Munich resumed their Bundesliga campaign with a 2-0 win over Borussia Monchengladbach. Mario Gotze struck after just seven minutes before Thomas Muller's penalty wrapped up the victory for Pep Guardiola's side who are 10 points clear at the top of the table.
Moyes has already travelled to Italy earlier this month to watch Juventus midfielder Claudio Marchisio as well as Cagliari's 27-year-old centre-back Davide Astori.
Meanwhile, United confirmed on Friday evening that they have agreed a club-record £37 million fee for Juan Mata, with the Spain international set to undergo a medical and complete personal terms.
Mata will need to be registered by Monday lunchtime in order to make his debut against Cardiff City on Tuesday.