El Chicharito is thought to be a summer target for Jose Mourinho's side after impressing during his first season with United. The 22-year-old has scored 20 times in 44 appearances and won the fan-voted Sir Matt Busby Player of the Year award.
"Real Madrid are a very big club, but then so are Manchester United," agent Eduardo Hernandez told goal.com. "I think this is a subject between directors. We would expect to look closely at any offer from Real Madrid, if Manchester told us there was one.
"We would only look at it, though, because in the first place Javier is extremely grateful to Manchester for having given him this chance, and also because it is reciprocated from the club."
Hernandez added that now would not be "the right time" for his client to leave United. Chicharito is expected to be part of the club's Champions League final clash with Barca tomorrow.